Fatir 35:39

Huwa allathee jaAAalakum khala-ifafee al-ardi faman kafara faAAalayhi kufruhu walayazeedu alkafireena kufruhum AAinda rabbihim illamaqtan wala yazeedu alkafireena kufruhum illakhasara

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.

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.