Mark Driscoll finally made it official: He’s starting a new church in Phoenix. The culmination of a comeback that has been gaining steam over the past year, the former Mars Hill pastor announced the news of The Trinity Church on Monday by email, Twitter and a new website. In a folksy video on the site, which begins with a “howdy†from Driscoll, the pastor said he and his wife, Grace, sitting by his side, were “hoping, trusting, praying, planning and also a little†— he made a jokey grimace — “worrying about planting a church here.â€