Allah says:

يٰٓأَيُّهَا الَّذِينَ ءَامَنُوا تُوبُوٓا إِلَى اللَّهِ تَوْبَةً نَّصُوحًا

Yaaa ayyuhal-lazeena aamanoo toobooo ilallaahi tawbatan nasoohaa.

O you who have believed, repent to Allah with sincere repentance.

Reference: Surah At-Tahrim 66:8