Belief is not a gift from God. Belief is man's reaction to God's good news, the Gospel of Jesus.Belief is a gift from God. Not all receive tht gift and are saved. Many act as if they've figured it all out on their own and now believe the Father sent the Son to die for our sins.
"How then shall they call on Him in whom they have not believed? And how shall they believe in Him of whom they have not heard? And how shall they hear without a preacher? And how shall they preach unless they are sent? As it is written:
'How beautiful are the feet of those who preach the gospel of peace,
Who bring glad tidings of good things!'
But they have not all obeyed the gospel. For Isaiah says, “Lord, who has believed our report?” So then faith comes by hearing, and hearing by the word of God." - Rom 10:14-17