Since God hates incest, why does he allow incest to happen at all?

Matthew 15:19“From the heart come evil thoughts, murder, adultery, all sexual immorality, theft, lying, and slander.”

Mark 7:21-22“From within, out of a person’s heart, come evil thoughts, sexual immorality, theft, murder, adultery, greed, wickedness, deceit, lustful desires, envy, slander, pride, and foolishness.”

Romans 1:24-26So God abandoned them to do whatever shameful things their hearts desired. As a result, they did vile and degrading things with each other’s bodies. They traded the truth about God for a lie. . . . That is why God abandoned them to their shameful desires.

Romans 6:12Do not let sin control the way you live; do not give in to sinful desires.

Romans 13:12-14The night is almost gone; the day of salvation will soon be here. So remove your dark deeds like dirty clothes, and put on the shining armor of right living. Because we belong to the day, we must live decent lives for all to see. Don’t participate in the darkness of wild parties and drunkenness, or in sexual promiscuity and immoral living, or in quarreling and jealousy. Instead, clothe yourself with the presence of the Lord Jesus Christ. And don’t let yourself think about ways to indulge your evil desires.

Galatians 5:19-26When you follow the desires of your sinful nature, the results are very clear: sexual immorality, impurity, lustful pleasures, idolatry, sorcery, hostility, quarreling, jealousy, outbursts of anger, selfish ambition, dissension, division, envy, drunkenness, wild parties, and other sins like these. Let me tell you again, as I have before, that anyone living that sort of life will not inherit the Kingdom of God. But the Holy Spirit produces this kind of fruit in our lives: love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control. There is no law against these things! Those who belong to Christ Jesus have nailed the passions and desires of their sinful nature to his cross and crucified them there. Since we are living by the Spirit, let us follow the Spirit’s leading in every part of our lives. Let us not become conceited, or provoke one another, or be jealous of one another.

Ephesians 4:17-24Live no longer as the Gentiles do, for they are hopelessly confused. Their minds are full of darkness; they wander far from the life God gives because they have closed their minds and hardened their hearts against him. They have no sense of shame. They live for lustful pleasure and eagerly practice every kind of impurity. But that isn’t what you learned about Christ. Since you have heard about Jesus and have learned the truth that comes from him, throw off your old sinful nature and your former way of life, which is corrupted by lust and deception. Instead, let the Spirit renew your thoughts and attitudes. Put on your new nature, created to be like God—truly righteous and holy.

Ephesians 5:3Let there be no sexual immorality, impurity, or greed among you. Such sins have no place among God’s people.

1 Thessalonians 4:3-7God’s will is for you to be holy, so stay away from all sexual sin. Then each of you will control his own body and live in holiness and honor—not in lustful passion like the pagans who do not know God and his ways. Never harm or cheat a fellow believer in this matter by violating his wife, for the Lord avenges all such sins, as we have solemnly warned you before. God has called us to live holy lives, not impure lives.

2 Peter 2:19They promise freedom, but they themselves are slaves of sin and corruption. For you are a slave to whatever controls you.

Jude 1:4, 18-19I say this because some ungodly people have wormed their way into your churches, saying that God’s marvelous grace allows us to live immoral lives. The condemnation of such people was recorded long ago, for they have denied our only Master and Lord, Jesus Christ. . . . They told you that in the last times there would be scoffers whose purpose in life is to satisfy their ungodly desires. These people are the ones who are creating divisions among you. They follow their natural instincts because they do not have God’s Spirit in them.

God clearly warns us to stay away from all sexual immorality, but in this life he allows us to make choices to sin. Incest, like every other vile sin, is the result of evil choices by fallen human beings who are far from God. We can be certain that God is aware of all such sin, that he is angered by it, and that he will see that just punishment prevails.

Ezekiel 22:10-15“Within your walls live men who commit adultery with their neighbors’ wives, who defile their daughters-in-law, or who rape their own sisters. . . . They never even think of me and my commands, says the Sovereign Lord. But now I clap my hands in indignation over your dishonest gain and bloodshed. . . . I will scatter you among the nations and purge you of your wickedness.”

1 Corinthians 10:8We must not engage in sexual immorality as some of them did, causing 23,000 of them to die in one day.

Ephesians 5:5-6You can be sure that no immoral, impure, or greedy person will inherit the Kingdom of Christ and of God. For a greedy person is an idolater, worshiping the things of this world. Don’t be fooled by those who try to excuse these sins, for the anger of God will fall on all who disobey him.

Colossians 3:5-6So put to death the sinful, earthly things lurking within you. Have nothing to do with sexual immorality, impurity, lust, and evil desires. Don’t be greedy, for a greedy person is an idolater, worshiping the things of this world. Because of these sins, the anger of God is coming.

Hebrews 13:4Give honor to marriage, and remain faithful to one another in marriage. God will surely judge people who are immoral and those who commit adultery.

Jude 1:7Don’t forget Sodom and Gomorrah and their neighboring towns, which were filled with immorality and every kind of sexual perversion. Those cities were destroyed by fire and serve as a warning of the eternal fire of God’s judgment.

Revelation 21:8“But cowards, unbelievers, the corrupt, murderers, the immoral, those who practice witchcraft, idol worshipers, and all liars—their fate is in the fiery lake of burning sulfur. This is the second death.”

Revelation 22:14-15Blessed are those who wash their robes. They will be permitted to enter through the gates of the city and eat the fruit from the tree of life. Outside the city are the dogs—the sorcerers, the sexually immoral, the murderers, the idol worshipers, and all who love to live a lie.

God will righteously judge all who are guilty of forcing the innocent into acts of incest and all adults who willingly participate together in such sin. Without the sincere confession and cleansing of sin and restitution, they cannot expect to participate in God’s promises related to heaven.