but hates the sin
Peter Kreeft, in his book Making Choices, says
“This is not a hairsplitting, abstract, technical distinction for scholars and theologians. It is crucial and practical. If we love the sin, we do not love the sinner, just as if we love the cancer, we do not love the patient.
There is a proper kind of hate. Even God has ‘wrath’ (unless Scripture lies). God does not hate any sinner, not even the worst. Jesus loved Judas to the last, and called him ‘friend.’ God loves Stalin and Hitler and Charles Manson, as David loved his rebel son Absalom, and for the same reason: He is our Father. But God hates sin, and so should we. To hate people is to lack compassion.”
If we doubt God’s love for the sinner and His hatred for sin, all we have to do is recall all the sinners (remember we are all sinners) who became saints despite their sinfulness. Saint Paul, the apostle to the Gentiles, imprisoned and condemned those who followed Jesus. Yet God loved him and forgave him. Saint Augustine, a Doctor of the Church, was guilty of living a hedonistic lifestyle, and for a period of time, was a pagan and a follower of several heretical cults. Yet God loved him and forgave him. Saint Francis of Assisi was a wealthy young man who was known for his love of the many pleasures in life and was a soldier for a time. Yet God loved him and forgave him. Saint Ignatius of Loyola was a proud and vain young man who sought glory in battle and the killing of those who were not Christian. Yet God loved him and forgave him.
All saints are and were sinners simply because we, all of humanity, are sinners. What sets them apart, what made them saints is that they came to love the sinner but hate the sin. They discovered the truth that comes to light only through the humble recognition of their own fragile humanity, that all they had been given was a gift, freely given, by their Creator. Nothing that they had achieved, nothing that they gained was through their sole power. They learned that “whoever exalts himself will be humbled, and the one who humbles himself will be exalted” [Lk 18:14].