The Rev. William Sloane Coffin is denouncing ministers who support the Persian Gulf war. "It's a heretical position," said Coffin, who was a leading voice against the Vietnam War. "They should follow their consciences." Coffin, 66, who is president of the national SANE/FREEZE coalition against the war, spoke at a luncheon in Detroit attended by Christians, Muslims, Jews and opponents of the war, saying some clergy are under "tremendous pressure" to support the war. "Somebody probably is plastering their churches with yellow ribbons and making sure everyone's wearing yellow ribbons," he said.