He spoke at Open Bible Fellowship Church, a small congregation in Morrison, Illinois, on November 2 - the second anniversary of his resignation as president of the 30 million-member National Association of Evangelicals.
The church's pastor, Chris Byrd, has been friends with Haggard for over 30 years.
"The first thing I want you to know is I sinned," Haggard told the congregants.
He revealed that at the age of seven a man who worked for his father had a "sexual experience" with Haggard.
"I didn't think anything of it and I tell you that not simply as an explanation, certainly not as an excuse," Haggard said.
After the incident, Haggard lived as if he never had such an experience: accepting Jesus into his life at age 16, meeting and marrying his wife Gail, having five children, and founding a successful megachurch in Colorado.
But at the age of 50, the same-sex incident came back to haunt him.
"There I was, 50 years old, a conservative Republican, loving the word of God, an evangelical, born-again, spirit-filled, charismatic, all those things," he said. "But some of the things that were buried in the depths of the sea from when I was in second grade started to rage in my mind and in my heart."
He recalls driving to his church in the middle of the night in September 2006 and praying, "God, do whatever it takes to deliver me."
"I thought do whatever it takes. I'll lay anything on the altar. I hate this thing, but there were times I loved it," Haggard remembered.
"I'd walked around the auditorium in the middle of the night thinking this is going to cost me everything," Haggard recalled. "This incredible war was going on inside of me."
During one intense prayer session before the scandal broke out, Haggard remembered feeling a deep connection with God and firmly vowing to "never do it again".
In the sermon, he did not say specifically what "it" was and how he had sinned, but former gay prostitute Mike Jones had accused him of immoral acts of sex and crystal meth use.
After Haggard made his promise to God, he said he felt like a demonic power spoke to him and said, "All hell will break loose on you because of this."
Then a few months later in November 2006 news of Haggard's sex scandal made headlines around the world with a newspaper carrying the headline, "All Hell Broke Out at New Life Church".
