Mr Overcomer says he was kicked out of the community when he started to question Cooper two years ago and refused to submit to his rule.
He told TV One's Sunday programme that he asked Cooper about his sexual abuse charges, and if it was right that he was a leader in the community.
'"Do you think it's right that you're a leader here?' Because as far as I knew, the scripture said that [the leader] had to be blameless outside the church as well. Obviously no convictions like that anyway, and he said I had no right to ask him those kinds of questions.
"He puts his hands on my head and says, 'Elijah, in the name of Jesus Christ, you've got evil spirits in you'."
Mrs Overcomer was a member of the Gloriavale community for 27 years. She left to be with her banished husband with their three small children and a fourth on the way, but said it took "a long time to get all that indoctrination out".
"Basically they just told me there was no way I could be with my husband," she told the Sunday programme. "He was 'evil deceived, full of the devil. You're damning yourself and your kids. There's no chance for any of your family if you go as well'."
She said they had no phone, or contacts on the outside.
"So we were basically going to go out, take a tent, then go from there."
They got a lift to Christchurch, and when the car broke down, a stranger offered to lend them his own.
Mrs Overcomer's sister Joy Courage also left the community in late 2013 with husband Mordecai.
They told the Sunday programme they left the commune after their secret relationship was discovered.
Sunday reported last night that a total of 65 people have left in the past eight years, including 22 in the past two months.
The rest of Mrs Overcomer and Mrs Courage's family are still living inside Gloriavale.
Sunday approached Gloriavale for comment and they replied in a statement:
"We do not make comment about other people or accusations they make about us to the media.
"Our trust is in God and he is still on the throne. His judgements are righteous."
Inside Gloriavale
The Gloriavale Christian Community has more than 500 members and was founded in 1969. It is located at Haupiri, inland from Greymouth on the West Coast. It relocated from its original North Canterbury site in Cust (where it was known as the Springbank Christian Community) to Haupiri in 1991. The community is totally self-contained.