As regards your interesting remarks on "conservatives" and "liberals" ("Why the Evangelical Church Needs the Liberal Church" and "Why the Liberal Church Needs the Evangelical Church"), it might be a help to look at the policy and company of Jesus. When he selects his 12 apostles, one is Matthew, a tax collector considered by many to be a traitor to their national cause and an outcast. Another one was Simon, a zealot - a name that meant he was a fundamentalist, a nationalistic fanatic. They were the two extremes in the politically and religiously polarized society in which Jesus lived.
In our own society and church we would call those extremes the "right" and the "left," the conservatives and the liberals. Maybe Jesus gave us a hint on how to deal with situations like that when they were sitting together at table with him.