A Pennsylvania pastor charged with breaking United Methodist law for officiating over his son's marriage to another man faces the possibility of being defrocked.

The Rev. Frank Schaefer, pastor at Zion United Methodist Church of Iona in Lebanon, faces suspension or the possibility of being defrocked for presiding over the 2007 wedding of his son Tim in Massachusetts, which legalized gay marriage in 2004.

Schaefer's trial is scheduled to begin Monday in Spring City and could last up to 3 days.

“Public opinion has changed very rapidly,” Tim Schaefer, 29, told the AP. “I hope this leads to a renewed conversation to revisiting these policies to see if they are a little archaic.”

Frank Schaefer said that he informed his superiors that he planned to officiate at his son's wedding before the ceremony took place.

It wasn't until 26 days before the church's statute of limitations would have expired that a complaint was filed against Schaefer by one of his congregrants that the church took action against him.

He is accused of breaching the church's Book of Discipline, the denomination's law book, which prohibits clergy from performing “ceremonies that celebrate homosexual unions.”

The Book of Discipline, Schaefer said, calls on him to “minister to everybody” equally.