Causes of deception

O you people, the promise of God is true. So do not let the life of this world delude you, nor let that (arch) deceiver deceive you about God.

Satan is certainly your enemy, so hold him as a foe. He only calls his faction to be the residents of Hell.

For those who are unbelievers, there is severe punishment; but for those who believe and do the right is forgiveness and a great reward.

Can he, the evil of whose deed is made to look attractive to him so that he considers it good, (be like him who is guided)? God leads whosoever He please astray and guides whosoever He will. So do not waste away your self with grief for them. God is indeed cognisant of things they do.