It is true that God, who is perfectly holy and righteous, always hates sin. It is also true that God loves sinners, but only repentant sinners.
However, this simplistic dichotomy between the sinner and his sin is false. Paul says that God is wrathful against all sin, “For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men” (Rom 1:18). But the same Paul also says that God is wrathful against all evildoers, “But because of your hard and impenitent heart you are storing up wrath for yourself on the day of wrath when God’s righteous judgment will be revealed” (Rom 2:5). Sinners who repented of their sins “were by nature children of wrath, like the rest of mankind” (Eph 2:3).
In the Old Testament, God expresses his hate of all wicked people, “The boastful shall not stand before your eyes; you hate all evildoers.” On Judgment Day, God will “destroy those who speak lies” because he “abhors the bloodthirsty and deceitful man” (Psa 5:5-6). Again, the Psalmist says that God condemns the wicked, “his soul hates the wicked and the one who loves violence” (Psa 11:5).
In Noah’s day, God destroyed all the inhabitants of the world because “the wickedness of man was great in the earth, and that every intention of the thoughts of his heart was only evil continually… So the LORD said, ‘I will blot out man whom I have created from the face of the land…’” (Gen 6:5-7). God repeatedly sent his wrath on evildoers in Sodom, Gomorrah, Israel, and all the wicked nations that opposed his people.
In the New Testament, God continues to condemn sinners – not only the sin – to hell. Those who do not believe and repent of their sins “will not inherit the kingdom of God” (1 Cor 6:9-11). Jesus repeatedly speaks of sending “workers of lawlessness” to eternal torment in hell, “Depart from me, you cursed, into the eternal fire prepared for the devil and his angels” (Matt 25:41; Matt 7:23; see also Psa 6:8). On Judgment Day, all those not found in the book of life will be sent to the lake of fire (Rev 20:14-15).
All of these do not mean that God is whimsical. His eternal wrath is his just and holy response to unrepentant sinners. But his eternal love is his merciful and gracious response to those who repent of their sins, “For while we were still weak, at the right time Christ died for the ungodly… God shows his love for us in that while we were still sinners, Christ died for us” (Rom 5:6, 8).