إِلَّا مَن تَابَ وَءَامَنَ وَعَمِلَ عَمَلًا صَٰلِحًا فَأُولَٰٓئِكَ يُبَدِّلُ ٱللَّهُ سَيِّـَٔاتِهِمْ حَسَنَٰتٍ ۗ وَكَانَ ٱللَّهُ غَفُورًا رَّحِيمًا

Real virtue in the eyes of God is a man’s becoming God-fearing. Any virtue which makes a man fearless of God is, in fact, a sin, while that sin which makes a man God-fearing is in fact, in terms of its result, a virtue. If a man happens to commit a sin but later on, seeing the error of his ways rushes towards Him in repentance (tawbah) and seeks His pardon, then God will mercifully add this sin to the list of his virtues, because that had made him turn towards Him.

— Source: Tazkirul Quran (Maulana Wahiduddin Khan) via Quran.com (25:70)