Repentance has two parts
Q. 86. What is repentance unto life?
A. Repentance unto life is a saving grace, whereby a sinner, out of a true sense of his sin, and apprehension of the mercy of God in Christ, doth with grief and hatred of his sin, turn from it unto God, with full purpose of, and endeavor after, new obedience.
While I’m on the subject of repentance, perhaps a definition would help. The Westminster Shorter Catechism defines the term in two parts—a true sense of sin and an apprehension of God’s mercy in Christ.
As for the former, repentance begins with a change of heart and mind. Paul writes, “Godly grief produces a repentance that leads to salvation” (2Co 7:10). When sinners develop a hatred of sin—specifically, their own sin—they’ve experienced the first part of repentance.
Regarding the latter, repentance also involves “an apprehension of the mercy of God in Christ.” To apprehend something is to understand and perceive it. When sinners repent, they don’t turn away from sin to face nothing on the other side. They simultaneously reject sin while also seeking God’s mercy. They flee from the wrath to come by running to Christ (Mt 3:7).
Repentance is turning from sin toward Christ for salvation.
Let me clarify again that repentance, like faith, is “a saving grace.” When God removes the heart of stone from one’s flesh and puts in its place a new heart of flesh, he will never be the same (Eze 36:26). He will crave God’s mercy more than sin. In short, he will repent.