A person who realizes their sin is sinful, and they want to stop it, and then they actually make a genuine effort to stop, is repentant. If that person comes to believe the only way to have forgiveness is to ask God for it through Jesus’ payment around A.D. 30, they will have their sins forgiven and all will be well with their soul when they die. This person is a candidate for admission to membership in a New Testament-era, Bible-believing Christian church.
A person who does something God says is wrong, is a sinner. A person who does something God says is wrong and has no plans or desire to stop, is not repentant. An unrepentant sinner is (by definition) not a Christian. This person is not a candidate for admission to church membership.
To be married at a (good*) Christian church, you have to be a member in good standing – i.e., a Christian. NOT an unrepentant sinner.
One of the (very few) things God said was abominable enough to warrant a death sentence under the Old Testament laws, was homosexuality. God doesn’t change. What used to be abominable to God remains abominable. The government and the dispensation have changed and we don’t stone people to death under the New Testament for being homosexual. The activity is still a sin but now they are given time and opportunity to repent.
Someone who is sexually and otherwise attracted to members of the same sex is not necessarily a sinner. Someone who acts out on their attraction may end up a sinner. One who engages in homosexuality and delights in it, revels in it, and announces to the world they intend to continue in it for the rest of their life, is an unrepentant sinner. The “gay marriage” is a celebration of the fact they intend to live as an unrepentant sinner, openly and unashamed.
Marriage is the very first human institution ever invented. It was invented by God, and was “a man plus a woman is a family.” A “gay marriage” is not only a celebration of open sinfulness, it is a perversion of the institution of Marriage. For a Christian minister to marry a pair of homosexuals should violate his conscience in three ways at least.
If a person is a murderer in the middle of a killing spree, they will not be admitted to my church’s membership rolls. Likewise, someone who has a hobby of getting high on heroin and driving at 100MPH through neighborhoods. A whore. A career burglar. If an UNrepentant sinner seeks admission, they will be denied. This is based on our religious belief.
*Courts have no business telling churches what to believe. But they will, because the churches are not treating people equally. Some “bad” churches let out their spaces for weddings to just-anyone without regard to anything BUT the homosexual/straight status of the participants. That is asking for lawsuits. This is the type of church that is going be sued with the lawsuit that gets my church’s tax-exempt status revoked in a broad-brush decision by an activist judge. Wait for it.