A Pennsylvania pastor refuses to voluntarily surrender his ordination credentials and says he cannot promise to uphold United Methodist Church doctrine, even after he was punished for marrying his gay son to another man.

The Rev. Frank Schaefer of Lebanon, Pa., was found guilty in a church trial last month, and given a 30-day suspension by a jury of 13 fellow clergy members. Part of the penalty was also a choice to either denounce same-sex marriage, or give up his role as pastor at the end of his suspension. Schaefer will go before the Board of Ordained Ministry Thursday for a final decision on his fate.

Standing with about 30 other church members at a press conference in Philadelphia Monday morning, Schaefer signed a petition asking for an end to LGBT discrimination. The 51-year-old said he doesn’t know what will happen next, but that he’s been contacted by the Episcopal church and other denominations regarding his career, the Associated Press reports.

“I wanted to find a way of answering truthfully and still keep my credentials in the church,” said Schaefer, who has been a United Methodist pastor for the last 17 years. “I have really wrestled and agonized over this, but finally came to the conclusion that my honest answer has to be no. I cannot uphold the Book of Discipline in its entirety. In fact, I don’t believe anybody can.”

The Book of Discipline of the United Methodist Church (UMC) teaches its subscribers to accept gay and lesbian Christians as members, but reject the practice of homosexuality as “incompatible with Christian teaching.” All clergy members are forbidden from presiding over weddings between two people of the same gender. Schaefer on Monday said the law was “filled with competing and contradictory statements.”

In 2007, Schaefer defied UMC doctrine when he married his oldest son, Tim, to another man in Massachusetts, the first state in the U.S. to legalize same-sex marriage. Schaefer said he had long been a supporter of LGBT rights, but that he had chosen not to preach on the issue in his conservative community. Once tried, however, Schaefer said he was done being a “silent supporter” of his three gay children, and of every other LGBT member of his church.

Schaefer’s was the first trial since the worldwide General Conference in 2012 last reaffirmed the United Methodist Church’s position on homosexuality. As the marriage equality movement makes historic gains across the country, however, a growing number of Methodist pastors are finding it impossible to minister to all people–as their church instructs–while simultaneously denying gay and lesbian members the right to marry. A handful or so more trials look to be on the horizon, including one for a retired bishop, the highest-ranking clergy member to have publicly presided at a same-sex marriage.