God.

Psalm 50:6
And the heavens proclaim His righteousness, for God Himself is Judge. Selah

Acts 17:31
For He has set a day when He will judge the world with justice by the Man He has appointed. He has given proof of this to all men by raising Him from the dead."

Romans 2:16
This will come to pass on that day when God will judge men's secrets through Christ Jesus, as proclaimed by my gospel.

Hebrews 13:4
Marriage should be honored by all and the marriage bed kept undefiled, for God will judge the sexually immoral and adulterers.

2 Peter 2:9
if all this is so, then the Lord knows how to rescue the godly from trials and to hold the unrighteous for punishment on the day of judgment.

Therefore.

1 Corinthians 5:1, 5, 7
It is actually reported that there is sexual immorality among you, and of a kind that is intolerable even among pagans: A man has his father's wife. . . .

Deuteronomy 13:5
Such a prophet or dreamer must be put to death, because he has advocated rebellion against the LORD your God, who brought you out of the land of Egypt and redeemed you from the house of slavery, in order to turn you from the way the LORD your God has commanded you to walk. So you must purge the evil from among you.

Deuteronomy 17:7
The hands of the witnesses shall be the first in putting him to death, and after that, the hands of all the people. You must purge the evil from among you.

Deuteronomy 21:21
Then all the men of his city will stone him to death. You must purge the evil from among you, and all Israel will hear and be afraid.

Deuteronomy 22:21, 22, 24
she shall be brought to the door of her father's house, and there the men of her city will stone her to death. For she has committed an outrage in Israel by being promiscuous in her father's house. You must purge the evil from among you. . . .

Ecclesiastes 9:18
Wisdom is better than weapons of war, but one sinner destroys much good.

Matthew 18:17
If he refuses to listen to them, tell it to the church. And if he refuses to listen even to the church, regard him as you would a pagan or a tax collector.