For a number of years back in the early 80's we attended First Baptist downtown. At that time FBC and BETHEL BAPTIST (Which carries the name of the original combined church) held several joint events and services during the years. It was always a fun event and the congregations mixed perfectly causing many to regret that they were ever split in the first place.
As far as our Radical Christian Theology:
rad·i·cal
ˈradək(ə)l/
adjective
1.
(especially of change or action) relating to or affecting the fundamental nature of something; far-reaching or thorough.
"a radical overhaul of the existing regulatory framework"
synonyms: thoroughgoing, thorough, complete, total, comprehensive, exhaustive, sweeping, far-reaching, wide-ranging, extensive, across the board, profound, major, stringent, rigorous
"radical reform"
2.
advocating or based on thorough or complete political or social change; representing or supporting an extreme or progressive section of a political party.
"a radical American activist"
synonyms: revolutionary, progressive, reformist, revisionist, progressivist; More
noun
1.
a person who advocates thorough or complete political or social reform; a member of a political party or part of a party pursuing such aims.
A religion be it Christian, Jewish, Moslem, Hindu or anything else that remain's true to it's foundations and refuses to bend with new social changes and progressive agenda's is hardly radical... Indifferent, even Stoic perhaps but Radical? Not!