A former pastor who co-founded a Christian music festival has lost his bid to withdraw his guilty plea in a child sex abuse case.

Harry Thomas, 76, had argued that his plea was invalid because his testimony had not established an adequate factual basis for four charges against him.

However, an appellate court rejected those arguments in a ruling issued Friday, saying they were satisfied that Thomas’ testimony “sufficiently established (his) guilt."

The panel also upheld the 18-year sentence he received. The panel found Thomas, who must serve his full term before he can be freed, had reached the plea agreement “freely, knowingly and voluntarily.”

Thomas is the former pastor of Come Alive New Testament Church in Medford and co-founder of the Creation Festival, billed as the country’s largest Christian music festival. He had acknowledged sexually assaulting a 9-year-old, having sexual contact with three girls ages 7 to 9 and exposing himself to a girl.