My old standby . . .
The mainline has become the sideline en route to the flatline.
Christianity in America is facing some VERY tough challenges. The Dominical promise that the "gates of hell shall not prevail" is not a guarantee of success in any particular locale. 500 years ago the center of Christianity was in Rome, Wittenberg, and Geneva. Try to find a lot of vibrant Christian congregations in Europe today!
My move from broad evangelicalism to confessional Reformational Christianity was in recognition of the relative absence of the Gospel in the mainline and the frothy diversions from it in anthropocentric evangelicalism. If the dingy in my part of the world is going down, I want it to be a a faithful one. And, who knows, in the providence of God we may yet see a resurgence of faithful monergistic Christianity in America. I am constantly amazed at the growth of 5 pt. Calvinism at Southern Seminary under Mohler. Stats report something like 1/3 of the grads are soteriologically Calvinist. That will not cheer the Presbyterians among us (insofar as they are Baptists), but given the size of the SBC, it warms my heart to know that the Reformation still lives among the big hair and twang set.