Read and reflect on verse 557 from Surah An-Nisaa: for We have never sent any apostle save that he should be heeded by God's leave. If, then, after having sinned against themselves, they would but come...
وَمَا أَرْسَلْنَا مِنْ رَسُولٍ إِلَّا لِيُطَاعَ بِإِذْنِ اللَّهِ ۚ وَلَوْ أَنَّهُمْ إِذْ ظَلَمُوا أَنْفُسَهُمْ جَاءُوكَ فَاسْتَغْفَرُوا اللَّهَ وَاسْتَغْفَرَ لَهُمُ الرَّسُولُ لَوَجَدُوا اللَّهَ تَوَّابًا رَحِيمًا
for We have never sent any apostle save that he should be heeded by God's leave. If, then, after having sinned against themselves, they would but come round to thee and ask God to forgive them - with the Apostle, too, praying that they be forgiven - they would assuredly find that God is an acceptor of repentance, a dispenser of grace.