According to a lot of people, it’s not. One Christian observer (in a very popular article) claimed that it’s “really just hate” and asked rhetorically: “Where did that phrase come from? The Bible? Nope. Jesus? Nope. But many Christians sure do spout it like it is God-inspired scripture . . .” Another Christian, writing on the topic, opines: “This slogan is one of the most unbiblical ideas I’ve ever heard that get’s touted as if it were actually a verse in the Bible.”
We must distinguish between exact words or phrases appearing in the Bible, and ideas, concepts, or notions appearing in the Bible. The first quotation above seems to be talking about the first thing: the exact phrase. It’s true that the exact phrase is not in the Bible; I agree (neither is “Trinity” nor “transubstantiation” nor “pope”). The second quotation seems to realize this distinction and makes the much stronger claim that the “idea” is not in Scripture. That is false, as I will shortly demonstrate.
Today, very often, saying this phrase (or similar ideas) is automatically regarded as “hate” because that very distinction has been obliterated, by a generation of postmodern subjective relativism and hostility against the idea of objective, absolute truths (especially moral ones). To hate a sin today (as the predominant view of our culture) is the same thing as hating the sinner who commits it. To criticize just about anything anymore immediately becomes “hate”.
We can’t criticize anyone for anything or point out that they are committing any sort of sin because that is regarded as personally “attacking” them. A person (in this mentality) is what they do. This is why discussion with anyone who disagrees has gone to the dogs. This erroneous, illogical and unbiblical outlook has permeated almost all political discussion, and more and more, theological and ethical discussion. No one can disagree with anyone anymore: is what this mindset amounts to.
Is “hating sin” some unbiblical novelty? Does it mean we also have to hate the sinner who commits the sin? No on both counts (we’d all have to hate ourselves if so, because we’re all sinners). Regardless of whatever is fashionable and chic and the latest fad and fashion in society (what gets us into all the coveted cliques and clubs and companies), the Bible offers this principle, among many others, and it remains true for all time. It expresses the notion, as applied to our behavior:
Psalm 45:7 (RSV, as throughout) you love righteousness and hate wickedness. Therefore God, your God, has anointed you with the oil of gladness above your fellows;*Psalm 97:10 The LORD loves those who hate evil; . . .
Psalm 101:3 I will not set before my eyes anything that is base. I hate the work of those who fall away; it shall not cleave to me.Psalm 119:104 Through thy precepts I get understanding; therefore I hate every false way. (cf. 119:128)Psalm 119:163 I hate and abhor falsehood, but I love thy law.Proverbs 8:13 The fear of the LORD is hatred of evil. Pride and arrogance and the way of evil and perverted speech I hate.Proverbs 3:5 A righteous man hates falsehood, . . .*Sirach 10:7 Arrogance is hateful . . . before men, and injustice is outrageous . . .Sirach 15:13 . . . abominations . . . are not loved by those who fear him.Sirach 17:26 Return to the Most High and turn away from iniquity, and hate abominations intensely.Sirach 19:6 and for one who hates gossip evil is lessened.Revelation 2:6 . . . you hate the works of the Nicola’itans, which I also hate.
Isaiah 61:8 For I the LORD love justice, I hate robbery and wrong; . . .*Malachi 2:16 . . . I hate divorce, says the LORD the God of Israel, . . .*Judith 5:17 . . . the God who hates iniquity is with them.*Sirach 10:7 Arrogance is hateful before the Lord . . . and injustice is outrageous . . .*Sirach 15:13 The Lord hates all abominations, . . .*Hebrews 1:9 Thou hast loved righteousness and hated lawlessness; therefore God, thy God, has anointed thee with the oil of gladness beyond thy comrades. [God the Father describing God the Son: Jesus]*Revelation 2:6 Yet this you have, you hate the works of the Nicola’itans, which I also hate.
Romans 12:9 Let love be genuine; hate what is evil, hold fast to what is good;
Since Paul has stated the principle of “hate the sin, love the sinner” (just in different words, but the same thought), and we are to imitate him, just as he also imitates God, then it’s beyond all question that the Bible teaches the notion and that, accordingly, we need to accept that and apply it in our lives.
John 8:3-11 The scribes and the Pharisees brought a woman who had been caught in adultery, and placing her in the midst  they said to him, “Teacher, this woman has been caught in the act of adultery.  Now in the law Moses commanded us to stone such. What do you say about her?”  This they said to test him, that they might have some charge to bring against him. Jesus bent down and wrote with his finger on the ground.  And as they continued to ask him, he stood up and said to them, “Let him who is without sin among you be the first to throw a stone at her.”  And once more he bent down and wrote with his finger on the ground.  But when they heard it, they went away, one by one, beginning with the eldest, and Jesus was left alone with the woman standing before him.  Jesus looked up and said to her, “Woman, where are they? Has no one condemned you?”  She said, “No one, Lord.” And Jesus said, “Neither do I condemn you; go, and do not sin again.”
Matthew 9:9-13 As Jesus passed on from there, he saw a man called Matthew sitting at the tax office; and he said to him, “Follow me.” And he rose and followed him.  And as he sat at table in the house, behold, many tax collectors and sinners came and sat down with Jesus and his disciples.  And when the Pharisees saw this, they said to his disciples, “Why does your teacher eat with tax collectors and sinners?”  But when he heard it, he said, “Those who are well have no need of a physician, but those who are sick.  Go and learn what this means, `I desire mercy, and not sacrifice.’ For I came not to call the righteous, but sinners.”
Luke 7:34-48 The Son of man has come eating and drinking; and you say, `Behold, a glutton and a drunkard, a friend of tax collectors and sinners!’  Yet wisdom is justified by all her children.”  One of the Pharisees asked him to eat with him, and he went into the Pharisee’s house, and took his place at table.  And behold, a woman of the city, who was a sinner, when she learned that he was at table in the Pharisee’s house, brought an alabaster flask of ointment,  and standing behind him at his feet, weeping, she began to wet his feet with her tears, and wiped them with the hair of her head, and kissed his feet, and anointed them with the ointment.  Now when the Pharisee who had invited him saw it, he said to himself, “If this man were a prophet, he would have known who and what sort of woman this is who is touching him, for she is a sinner.”  And Jesus answering said to him, “Simon, I have something to say to you.” And he answered, “What is it, Teacher?”  “A certain creditor had two debtors; one owed five hundred denarii, and the other fifty.  When they could not pay, he forgave them both. Now which of them will love him more?”  Simon answered, “The one, I suppose, to whom he forgave more.” And he said to him, “You have judged rightly.”  Then turning toward the woman he said to Simon, “Do you see this woman? I entered your house, you gave me no water for my feet, but she has wet my feet with her tears and wiped them with her hair.  You gave me no kiss, but from the time I came in she has not ceased to kiss my feet.  You did not anoint my head with oil, but she has anointed my feet with ointment.  Therefore I tell you, her sins, which are many, are forgiven, for she loved much; but he who is forgiven little, loves little.”  And he said to her, “Your sins are forgiven.”