The gospel reveals the righteousness of God, both in his mercy and wrath. No one deserves salvation, but God being rich in mercy gives faith to some for them to understand his righteousness. Paul quoted Moses saying; God shows mercy to whom he wills and shows compassion to whom he wills(Rom 9:15). Therefore it is God who shows mercy to some and punishes others as an expression of justice. Now is God unfair? By human “standards” of fairness, yes he is! If he is fair, then we’re all hell bound. Scripture says that no one is righteous and that all have sinned and fall short of the glory of God, but being merciful he bestowed salvation to those who have faith in him.