Is, then, he to whom the evil of his own doings is [so] alluring that [in the end] he regards it as good [anything but a follower of Satan]? For, verily, God lets go astray him that wills [to go astray], just as He guides him that wills [to be guided]. Hence, [O believer,] do not waste thyself in sorrowing over them: verily, God has full knowledge of all that they do!