Recently I came across two comments about liberalism within the Christian church that struck me:
Liberal theology cannot sustain a local congregation. It kills churches. In fact, it only survives due to tenured academics. Rick Warren 
Congregationally speaking, Protestant liberalism is deader than Henry VIII. While survey after survey shows a secularizing American population, this hasn't helped the growth of liberal Protestant churches. Where are the Unitarian mega-churches, the Episcopalian church-planting movements? Russell D. Moore 
As both comments have implications for church growth I thought I would explore them with the help of some system dynamics.
Note that the Rick Warren comment refers to liberal theology, but the Russell Moore comment refers to liberal churches. The two concepts are related but not identical. For now though I will define a liberal church as one with a liberal theology, realising that this is not the whole story.
A liberal theology refers to a method of arriving at truth which uses scripture as a general, and non-exclusive, guide rather than as a set of propositions that must be believed. Thus rather than scripture indicating a fixed canon of belief for all time, its truths may be modified according to the age. Unlike orthodoxy the bias of the human authors of scripture can be questioned, and even the text itself. Material from outside the Bible, such as history and tradition, may have equal value in determining truth, all weighed by human reason. Thus in a liberal church there is never a fixed set of beliefs. Such a church will be lenient over what it considers the faith, and would expect diversity within its midst.
Now I suspect that this definition does not do justice to the use of the word “liberal” by many people, including Christians who call themselves liberal. There are degrees of liberalism, and some may emphasise liberalism in behaviour more than that of doctrine, and vice versa. But hopefully this is sufficient to examine the church growth implications of the Warren and Moore quotes, and expand them a bit.
By contrast a conservative church holds to a conservative theology which is fixed by scripture alone for all time. Thus a conservative church will (or should) be strict over what it considers the faith.
Where Do Liberal Churches Come From?
Both Warren and Moore indicate that liberal churches are inherently weak; they hasten church decline (Warren), and they are unable to start new churches (Moore). The fact remains that although the denominations that are dominated by liberal beliefs are declining the fastest, and have been since Dean Kelley’s  study from the 1970s, they do not decline that fast. So why are there still liberal churches? Why do they survive, and in some cases thrive?
I will put forward three reasons:
1. Church Leaders Liberalise, but Members Remain Conservative
One reason church leaders liberalise is that the seminary system encourages liberal beliefs in church leaders. I think that is what Rick Warren was getting at when he said, “it only survives due to tenured academics”. A similar point was made by sociologist Rodney Stark, who in a book review, suggested European churches suffered from “institutionalised clerical atheism” , i.e. the institution of the church encourages doubt in its ministers. My suggestion is that this is aided in part by the seminary/ theological college system of training, the institution that affects the belief system of those it trains.
Thus in this scenario those who are called into full time ministry are sent away to a college, where they learn theology at the hands of academics with liberal beliefs. They are then sent to conservative congregations and spend their ministry trying to change their people’s views with the “latest scholarship” they picked up at seminary.
(i) First result of liberal leadership
One potential result of the liberal ministry is that those who are conservative in the congregation leave and go elsewhere. The church in which I was initially raised is an example of this. In common with many Welsh Presbyterian churches it was rooted in the conservative evangelical theology of the 18th century revivals. When the 1960s started a liberal minister came, who taught people to doubt the orthodoxy they had received. In ten years the church emptied from a few hundred to only a handful of members, as people left and found other conservative churches. After another decade the church was closed. This was repeated across the UK, so for a while the number of liberal churches grew, but not all their people were liberal. As such the number of members in liberal churches declined, firstly through transfer then through death, lack of young people and inadequate conversion.
Figure 1 expresses these ideas. The more people in church the more become leaders, the more liberalise and the more liberal teaching injected back into church. This teaching reduces conversion, reduces the number of children of church members who progress to membership, and increases, after some delay, the number who leave the churches so affected. All the loops are balancing loops sending the church numbers to zero.
|Figure 1: Liberal ministry causing church decline|
(ii) Second result of liberal leadership
A second result of a liberal ministry is that the most academic of the liberal ministers have such a difficult time in churches that they find a better role for themselves back in the academic environment. Thus they return to seminary as educators and the cycle of the seminary liberalising the next generation of ministers is complete. This is captured in the reinforcing loop of figure 2. The reinforcing nature of the loop suggests that the process of liberalising accelerates, and combined with figure 1 church decline accelerates.
The conservative churches that survive are strong and have a healthy membership. They send the larger numbers to seminary, but some of these trainee ministers become liberal and start the decline process again in the next batch of conservative churches to take on liberal ministers. Thus although a given liberal congregation may die in a couple of generations, liberalism, and liberal churches last much longer, fed by the seminary system that changes the beliefs of its conservative intake.
I think this has been the canonical evangelical view of the effects of liberalism on the church, and within which the Warren and Moore quotes are set. However I think there are more dynamics taking place than the above scenario suggests.
2. Church Members Liberalise, but Leaders Remain Conservative
In this scenario the minister is conservative but the congregation is in varying degrees of belief from conservative to liberal. These are not two distinct groups but a spectrum of people from one extreme to the other. Three results spring out.
(i) First result of conservative leadership
The liberal members leave and join liberal churches. Now at this point I am indebted to a medievalist blogger, Magistra, et Mater , who has used my models to examine the interaction between liberal and conservative churches . Starting with my concept of enthusiasts as the church members who are chiefly responsible for conversion, Magistra suggests that some of them cease to be enthusiasts because they lose enthusiasm for the conservative faith in which they were converted. Thus not only do they become inactive in evangelistic work, they become more liberal as well. There comes a point where such liberal people cannot fit into the church of their conversion, thus they leave and join a liberal church . They are now a specific source of recruitment to the liberal church.
These ideas are captured in figure 3, where the conservative church is in red and the liberal one in blue. The enthusiasts recruit from the unbelievers. After a time they cease recruiting and become inactive believers, initially conservative but later becoming liberal. They are still in the conservative church. Eventually the liberal members of the conservative church leave and join a liberal church, figure 3, part A .
|Figure 3: Sources of recruitment to liberal churches due to conservative churches|
(ii) Second result of conservative leadership
I will go further and suggest that there are a number of enthusiasts who get emotionally hurt by their church and also leave. I have noticed a tendency for such hurt people to reject the beliefs of those who hurt them, thus zealous conservative evangelicals abandon that version of the faith, because that was the belief system of the people they fell out with. After some time such hurt people also find a home in a more liberal church. Where beliefs are less strong, there is more tolerance and people are less likely to get hurt, figure 3, part B.
(iii) Third result of conservative leadership
Magistra describes another effect of the recruitment activities of an enthusiastic conservative church, that of negative evangelism. In this case the enthusiasts of the conservative church have a negative impact on unbelievers, turning them from the gospel message. She extends my model to include hardened unbelievers, who are no longer open to the message of the conservative church, figure 3 part C. However if they come across a liberal church, perhaps through the community work of that church, they might find less negative connotations, less demands made, less questions asked, and this is a happier home for their religious quest .
Thus I have suggested three sources of recruitment to the liberal church. The result is that rather than dying out, liberal churches can last many generations, albeit at the expense of conservative churches. I am not sure if this is a standard narrative as liberal churches see it. Perhaps someone could comment on this.
One side effect of this transfer of liberal people from conservative churches, is that it keeps conservative churches conservative. Strictness in maintaining doctrinal and behavioural standards leads to a strong church, according to Dean Kelley’s definition, which can attract and retain others . Thus the losses of the liberal people from the conservative church may be offset by conversion, and retention of those with conservative views, and net growth of the church could result.
3. Church Leaders and Members Liberalise Together
Here the issue is not just the interaction between liberal and conservative churches, but the interaction of church with an outside world not part of any church. For a church to grow it needs effective contact with that world. No church can afford to be so irrelevant it cannot get its message across. But the beliefs and practices of the world keep changing, thus there is pressure on the church to keep changing to keep itself relevant. Thus the church over time may change its beliefs in stages, to keep in step with culture, usually 10 to 15 years behind as change comes slowly in the church. Thus there is a slow evolution of practices and beliefs of minister and members alike.
For example, evangelical Christians are thought of as the more conservative end of Christianity, there is (in theory) a fixed creed and fixed set of behaviour patterns. However some evangelicals prefer to say they are “conservative evangelical” as they recognise that not all evangelicals are as true to that system of belief as they are. However there are also: "open evangelicals", “progressive evangelicals”, “small ‘e’ evangelicals”, “accepting evangelicals”, to name but a few! Each extra word flags that some aspect of belief, behaviour or attitude has, or could be modified. These are clear signs of a movement that is diversifying, which is another way of saying becoming more liberal.
I have proposed three reasons why liberal churches survive, maybe grow, or at least do not decline as fast as one might think: Seminaries generate liberal ministers; liberal people are generated by the actions of conservative churches; and conservative churches themselves liberalise to stay relevant. My research questions are:
1) What are the relative effects of the three scenarios? That is, which of the three has the strongest effect on the survival of liberal churches and which has the least, at any given time?
2) Are there other scenarios I have missed?
3) Do the two types of churches actually need each other to survive, as suggested by Magistra ? In other words is there a symbiosis between them that keeps the conservative true, and provides the liberals with new recruits?
A Spanner in the Works
This blog was originally meant to be a single article, but as ever the material and ideas keep expanding so it is now part one of two blogs, part two to follow. I will finish it by throwing a spanner in the works – I will query the definitions of conservative and liberal!
In the 1970s a former Methodist minister turned researcher, the aforementioned Dean Kelley, published a book entitled “Why Conservative Churches are Growing” . Looking at membership data of a range of denominations in the USA he demonstrated that whereas most of the conservative denominations were growing, the liberal ones were in varying stages of decline. As I write this blog it is still generally the case, although some conservative churches, such as the Southern Baptists, are now slowly declining . Again it is against this viewpoint that the comments by Warren and Moore were made.
However Kelley was the first to admit the title of his book was confusing [3, p.xvii]. His thesis was not about conservative churches, or growth; it was about strict churches being strong. Strong churches may grow, but there again they may not, depending on the context.
Thus a conservative church could be lenient (the opposite of Kelley’s strong) because it does not insist that all its members follow its beliefs or behaviour code, or because it does not direct much effort or zeal into evangelism. Discipline and missionary zeal are two of Kelley’s indicators of strictness. Such a church would be weak, which according to Kelley would include tolerating individualism, a reserve in sharing the faith, and a general lukewarmness for spiritual things. Such a church may be in decline despite its conservative beliefs.
By contrast a liberal church may be strict. Yes it tolerates a wide range of beliefs, but it does not tolerate those whose beliefs exclude others. A standard liberal creed is “we are tolerant of everything, except intolerance” . As such there are people who would not fit in such a liberal church, and would have to go elsewhere. All tolerance has bounds! Such a liberal church may be very vocal in proclaiming its stance, not in evangelism, but in campaigning and lobbying non-Christian groups in society. As such there would be considerable zeal for producing opinion change, which could easily result in recruitment. Such a church would be stronger than the conservative one mentioned above, and might well grow more.
The issues connected with growth are not just theological as the words “conservative” and “liberal” would imply, but organisational. How strictly does the church keep to its beliefs, ethos, and behavioural norms, whatever they are? The subject will be returned to in a later blog.
Church Growth Modelling, churchmodel.org.uk
Notes and References
 The comment first appeared on Facebook and Twitter February 2013
It has been reproduced on many other websites, and only came to my attention recently. Rick Warren is founder and leader of Saddleback Church in California.
 Quoted by:The Atlantic, July 25th 2013.
Russell D. Moore is president of the Southern Baptist Ethics & Religious Liberty Commission
 Dean Kelley, Why Conservative Churches are Growing: A Study in the Sociology of Religion. Mercer University Press, revised 1986, originally 1972.
 Rodney Stark, Review of Pentecostalism: The World their Parish. Review of Religious Research, 44(2), P.203, 2002. In the last paragraph he suggests that institutionalised clerical atheism is a barrier to church growth in Europe, and thus a subject worthy of investigation.
 Magistra et Mater: Where history, religion and motherhood meet and have a long intellectual conversation, http://magistraetmater.blog.co.uk/
 Magistra prefers to use the labels hard and soft church, rather than conservative and liberal. Hard church, soft church, no church. 24/7/08.
http://magistraetmater.blog.co.uk/2008/07/24/hard-church-soft-church-no-church-4494374/ . I will return to these definitions in a later blog.
 Magistra et Mater: Church growth, negative evangelism and beta churches. 22/4/13.
 Compare with the model in Magistra et Mater, Hard church, soft church and mission, 26/7/08.
 John S. Dickerson, The Decline of Evangelical America, The New York Times Sunday Review, 15/12/12.
 I was once part of a church growth research group that visited a liberal church working in an inner city area. They were the only church in the area. When one of the group asked the minister if any evangelical church had ever tried working in the area, he replied “No, and if they did he would run them out because they would upset the prostitutes and the gays!” The degree of strictness, dare I say intolerance, shocked even the more conservative members of our research group.