I referred to the idea of this post earlier, and finally found some time to get it out of my system. It is definitely part of the reason I am no longer the liberal I was brought up to be. My college degree is in theology, along with Christian Education. And yes, I studied both conservative and liberal theological ideas. (A lot of the liberal seminaries only teach the liberal views, mentioning conservative views only to mock them.)
At first glance, it might look like there is a sort of spectrum, with Liberal at one end and Conservative at the other, and individual people scattered out all along the line. And it often appears that way. But the real problem is, that "spectrum" is not all Christianity.
Liberal theology began in Europe in the 1700s in the universities and clergy of the state-supported "established" churches (the kind of thing the framers of our Bill of Rights intended to avoid). It was made possible by the institution of the professional clergy--men who made their living from the church and often had no clue how to make a living any other way. And from the very beginning there was an inherent dishonesty at its very core. There have always been people who cease to believe in Christianity; it even happens to pastors and other church leaders. Often such people walk away from the church and find other ways to make a living. I am saddened on behalf of such people, but I do not blame them for what they do; at least they have some integrity left. But those who started and maintained liberal theology left the beliefs of Christianity, and yet stayed in the professional ministry, stayed in the seminary faculties, stayed in the denominational organization--and lived a lie the whole time. In the local church, they used the same vocabulary as true believers but with their own definitions, different from those of historic Christianity. Among themselves, they developed new ideas about the origin of the Bible--all theories spun out of thin air, with no historical evidence to back anything up--and about everything based on the Bible. But they learned to be careful to hide their real beliefs, or lack of them, in public until they gained control. And overall, their beliefs were not the historic doctrines of Christianity.
And gradually, they did gain control of denominations, colleges and seminaries. Francis A. Schaeffer wrote about what had happened in the Northern Presbyterian denomination: In the 1890s, a professor at Union Theological Seminary was "defrocked" (officially put out of the ministry, his ordination revoked) for teaching liberal theology. But by the 1930s, J. Gresham Machen, one of the leading conservative theologians, was defrocked for being a conservative. The liberals had gained control of the denominational organization, and tightened that control after many conservatives left and formed a new Presbyterian body.
By the 1930s, all of what were called the "mainline" Protestant denominations were controlled by those who held to liberal theology. These included the Northern Presbyterians (now called the Presbyterian Church in the U.S.A. since merging with the Southern Presbyterians), the Episcopal Church, the American Baptists, the United Methodists, the Congregational-Christian Church (result of a merger between the Congregationalists, descended from the New England Puritans, and another group and now part of the United Church of Christ), the Evangelical Lutheran Church (the largest Lutheran body at that time). By the 1950s, a new denomination joined them--the Disciples of Christ, split off from the independent Christian Churches, a loose group with no denominational structure (the liberals proceeded to set one up).
Now, the control is not absolute and complete, especially at the local level. Even in the 1950s, often the members of the congregation were more conservative than their pastors. And individual congregations often were quite conservative and taught historic Christian doctrine locally. And not all pastors were completely liberal. I can remember when Don Wildmon, a Methodist minister, began to speak out on moral issues, he was upset that the press labeled him a "fundamentalist," a term from the '30s. He very likely held some liberal views on the Bible and theology, but was still morally conservative. But such people are now in the minority in these denominations and have little clout beyond the local level.
But what does all this have to do with politics? Well, liberal churchmen and liberal politicians have worked together for the past century in this country. There was a Religious Left long before anyone ever heard of a Religious Right in the '80s. The clergy of the liberal churches pushed for the welfare state from the beginning, and for every liberal cause since. And especially in the early years of the twentieth century, the backing of the pastors and denominations gave credibility to the plans of the liberal politicians.
The question boils down to, if a liberal pastor can stand up and lead his congregation in the Apostles' Creed or other historic statement of faith and not mean it--what does that imply about a liberal politician who is elected to office and takes an oath to uphold the Constitution? Can we trust him, if we can't trust his pastor?