CHICAGO (AP) — A Dallas pastor who took over leadership of the Rev. Jesse Jackson’s longtime civil rights organization resigned Tuesday just months after he took the job.

The Rev. Frederick Haynes III told The Associated Press that he submitted a letter with his resignation as head of the Chicago-based Rainbow PUSH Coalition, effective immediately.

“After a time of prayer and consultation, I felt it was best to step down as president and CEO of Rainbow PUSH,” he said by phone from Texas. “I am forever honored that the Rev. Jackson graciously considered me worthy of following him as president of the organization that he founded.”

Haynes, 63, said he felt it was “necessary” to move on in light of “challenges that continue to exist,” but declined to elaborate further. His resignation letter, written on Rainbow PUSH letterhead, also did not go into details about his decision.