The notion of 'cowboy church', however, got me thinking: how much do religious confessions and denominations shape their surrounding regions, and get shaped by them? Does the influence only go one way, or does it go back and forth? This would probably make a good subject for a Ph.D. in sociology or history, or even in theology. Let me suggest a few points in the hope of sparking some discussion.
My instinct is that Catholicism is an inherently urban denomination. That is, it will flourish best in towns and cities. These areas will tend to have the sorts of administrative framework that can best support a full time professional priesthood and episcopate, and allow these two key parts of the church to deal with each other. Further, Catholicism - with its focus on consecration and sacraments - becomes immensely difficult to observe without reasonably ready access to a priesthood. We can go even further with this idea. When Catholicism is active in frontier areas, it will tend to bring the City with it. We can see this in two areas. First, in mediaeval Europe, the Cistercian monks made their name in settling and farming remote and inhospitable areas. Their administrative systems and management style and success in farming, however, actually tended to create settlements (1). Second, Columbus' journeys were inspired at least in part by a belief that it would bring on the last days (2). When the Church followed in his wake to the new world, however, it backed itself up with that most organised of structures, the military.
My instinct is also that the Orthodox church, growing out of the great city of Byzantium, also might have done better in urban areas. This might explain its flourishing in the small towns and villages of Greece and Serbia. Perhaps the Russian Orthodox Church overcame the tyranny of distance in that vast empire with its connection to the powerful Tsarist state.
Methodism and the Salvation Army flourished among the English working class, and so they might be termed particularly urban denominations. On the other hand, it strikes me that the Protestant churches are particularly well adapted to rural and frontier life (which is why 'cowboy churches' seem like a genuinely meaningful form for worship to take). Having a greater focus on the Scriptures than the Eucharist means that consecration is less critical than literacy and the ability to preach and a temperament for pastoral care.
Looking at things in this way suggests that we might need to look at demographics and economics and geography as much as at theology in how churches flourish or wither. Knowing in what world someone lives and formed their character may well explain why they might most love (as Mitt Romney said)
... that profound ceremony of the Catholic Mass, the approachability of God in the prayers of the Evangelicals, the tenderness of spirit among the Pentecostals, the confident independence of the Lutherans ...It also suggests that maybe all churches should look a little kindly on those who go from one form of devotion to another: a cowboy-church adherent may find it as difficult to worship the Lord honourably in Times Square as a Greek Orthodox believer in the Kalahari desert.
(1) James Westfall Thompson, 'The Cistercian Order and Colonization in Mediaeval Germany' (1920) 24 American Journal of Theology 67 at 77.
(2) Leonard I. Sweet, 'Christopher Columbus and the Millennial Vision of the New World' (1986) 72 Catholic Historical Review 369.