Televangelist Thomas Isaac Rehan has scored quite a programming coup, with a very very very special guest scheduled to appear on the broadcast from his sprawling megachurch and compound in a former St. Louis, Missouri stadium. Yes, squeezed in among the promos for Catch Up With Jesus Ketchup and Rugged Cross Air Fresheners will be none other than the Lord of Hosts Himself/Herself/Themselves, in Peter Filichia's new play God Shows Up, opening tonight at The Playroom Theater. . . .