God hates evil and unrepentant evil people.
GOD designed the world to work in a specific way—the best way. He gave angels and men free will to choose how to live. When someone chooses to live inconsistently with GOD's design, the Bible calls that sin.
GOD hates sin because sin is against GOD's nature. In a way, sinful behavior is saying to GOD that we know better than He does, which is prideful. GOD hates a proud heart.
People tend to think of an evil person being someone who commits egregious crimes such as rape, murder, pedophilia, etc. While these qualify as evil, GOD sees an evil person as anyone who walks in sin, regardless of which sin. That means a liar is evil. An adulterer is evil. A thief is evil. And so on.
King Solomon wrote the following proverbs regarding these things:
17 A man who is without discernment and is lawless does not walk in good ways.
But he winks with an eye; he makes a sign with his foot,
And teaches with the wave of his hand.
18 And with a perverse heart, he constantly schemes evil things;
Such a man causes trouble in a city.
19 Therefore his destruction comes suddenly,
A deep and incurable wound.
20 For he rejoices in everything the Lord hates,
And he shall be broken because of his soul's uncleanness:
21 A haughty eye, an unrighteous tongue,
Hands that shed righteous blood,
22 A heart that devises evil thoughts,
And feet that hasten to do evil;
23 As a false witness he kindles injustice
And causes quarrels between brethren.
24 My son, guard the laws of your father,
And do not depart from the rules of your mother.
25 But fasten them to your soul continually
And wear them as a collar upon your neck.
(Proverbs 6:17-25 OSB)
The truth is that when we become a sinner, we become an enemy of GOD because we chose that which is inconsistent with His design and character. As the apostle Paul wrote to the Christians in Rome:
8 But God demonstrates His own love toward us, in that while we were still sinners, Christ died for us. 9 Much more then, having now been justified by His blood, we shall be saved from the wrath of God through Him. 10 For if while we were enemies we were reconciled to God through the death of His Son, much more, having been reconciled, we shall be saved by His life.
(Romans 5:8-10 NASB)
Despite our enemy combatant status, GOD is merciful and willing to forgive our sins. GOD gives us opportunity to repent. He understands our weak nature, that many of us don't actively want to position ourselves opposed to GOD. We just "fall" into that status (pun intended).
However, GOD knows our hearts. He understands our intentions—even before we do something. And eventually, GOD's patience with us runs out.
GOD warned the children of Israel of the severe consequences of hating Him. At Mount Sinai, GOD began the Ten Commandments as follows:
1 Now the Lord spoke all these words, saying:
2 “I am the Lord your God, who brought you out of the land of Egypt, out of the house of bondage. 3 You shall have no other gods before Me.
4 “You shall not make for yourself an idol or a likeness of anything in heaven above, or in the earth beneath, or in the waters under the earth. 5 You shall not bow down to them or serve them, for I, the Lord your God, am a jealous God, recompensing the sins of the fathers on the children to the third and fourth generation of those who hate Me; 6 but showing mercy to thousands, to those who love Me and keep My commandments.
(Exodus 20:1-6 OSB)
While the Ten Commandments and the Law of Moses no longer directly apply to Christians, Jesus reiterated this principle of consequences for walking in sin:
18 “To the angel of the church in Thyatira write:
These are the words of the Son of God, whose eyes are like blazing fire and whose feet are like burnished bronze. 19 I know your deeds, your love and faith, your service and perseverance, and that you are now doing more than you did at first.
20 Nevertheless, I have this against you: You tolerate that woman Jezebel, who calls herself a prophet. By her teaching she misleads my servants into sexual immorality and the eating of food sacrificed to idols. 21 I have given her time to repent of her immorality, but she is unwilling. 22 So I will cast her on a bed of suffering, and I will make those who commit adultery with her suffer intensely, unless they repent of her ways. 23 I will strike her children dead. Then all the churches will know that I am he who searches hearts and minds, and I will repay each of you according to your deeds.
(Revelation 2:18-23 NIV)
When a person willfully chooses a life of sin and is unrepentant, GOD hates that behavior and that person (as a result of their behavior). The Bible shows there are severe consequences for this wickedness. The Hebrews letter sums it up perfectly:
26 For if we go on sinning willfully after receiving the knowledge of the truth, there no longer remains a sacrifice for sins, 27 but a terrifying expectation of judgment and the fury of a fire which will consume the adversaries. 28 Anyone who has ignored the Law of Moses is put to death without mercy on the testimony of two or three witnesses. 29 How much more severe punishment do you think he will deserve who has trampled underfoot the Son of God, and has regarded as unclean the blood of the covenant by which he was sanctified, and has insulted the Spirit of grace? 30 For we know Him who said, “Vengeance is Mine, I will repay.” And again, “The Lord will judge His people.” 31 It is a terrifying thing to fall into the hands of the living God.
(Hebrews 10:26-31 NASB)