﴿ وَمَن كَفَرَ فَلَا يَحْزُنكَ كُفْرُهُۥٓ ۚ إِلَيْنَا مَرْجِعُهُمْ فَنُنَبِّئُهُم بِمَا عَمِلُوٓا۟ ۚ إِنَّ ٱللَّهَ عَلِيمٌۢ بِذَاتِ ٱلصُّدُورِ ﴾

“But as for him who is bent on denying the truth - let not his denial grieve thee: unto Us they must return, and then We shall make them [truly] understand all that they were doing [in life]: for, verily, God has full knowledge of what is in the hearts [of men].”

Please check ayah 31:24 for complete tafsir.