Mike Crowe has written a letter explaining "why people like me cannot support efforts to change the definition of marriage." His reason is that he believes God created marriage as a bond between a man and a woman, and we humans have no right to alter what God has established.
If that is his belief, then I fully understand why he would disapprove of same-sex marriages, and why people who share his belief would want to belong to a church that did not perform or recognize such marriages. He has a perfect right to hold this belief, to express it publicly, and to join any group that shares his creed.
Here's what I don't understand about Mr. Crowe's position: He seems to think that because he and some others have a religious belief that same-sex marriage is wrong, our government should forbid same-sex marriages even between people who don't share his belief. He wants the government to enforce his religious belief by denying to homosexuals the great benefits of a marriage contract.