Multiply, a new initiative by David Platt, pastor of The Church at Brook Hills, Birmingham, and author Francis Chan, will include two Multiply Gatherings led by Platt and Chan, Nov. 9, 7–10 p.m. via free webcast from The Church at Brook Hills and Nov. 10, 8–11 p.m. via free webcast from the SF City Impact Mission in San Francisco, Calif.…