To use the term "mainline" protestants is to confuse the situation. Many people do not realize what the term means. "Mainline" has become synonymous with "heresy." The "mainline" denominations are to Christians as the ADL is to devout Jews. That is to say, they reject the authority of the Word in favor of their own wicked desires.
I'm glad someone understands this. I'm not nearly as devout as I should be, but my favorite prayer is "Dear G-d, please tell Abe Foxman to SHUT UP!"