هُوَ الَّذِيْ جَعَلَكُمْ خَلٰۤىِٕفَ فِى الْاَرْضِۗ فَمَنْ كَفَرَ فَعَلَيْهِ كُفْرُهٗۗ وَلَا يَزِيْدُ الْكٰفِرِيْنَ كُفْرُهُمْ عِنْدَ رَبِّهِمْ اِلَّا مَقْتًا ۚوَلَا يَزِيْدُ الْكٰفِرِيْنَ كُفْرُهُمْ اِلَّا خَسَارًا ( فاطر: ٣٩ )
Huwal lazee ja'alakum khalaaa'ifa fil ard; faman kafara fa'alaihi kufruhoo; wa laa yazeedul kaafireena kufruhum 'inda Rabbihim illaa maqtanw wa la yazeedul kaafireena kufruhum illaa khasaaraa (Fāṭir 35:39)
It is He who has made you successors upon the earth. And whoever disbelieves – upon him will be [the consequence of] his disbelief. And the disbelief of the disbelievers does not increase them in the sight of their Lord except in hatred; and the disbelief of the disbelievers does not increase them except in loss. (Fatir  : 39)
1 Mufti Taqi Usmani
He is the One who has made you successors (of the past generations) on the earth. So the one who becomes infidel, his infidelity will go against himself. Their infidelity adds nothing to the infidels but anger from their Lord, and their infidelity adds nothing to the infidels but loss.