Answer: Only by faith in Jesus Christ and in his substitutionary atoning death on the cross; so even though we are guilty of having disobeyed God and are still inclined to all evil, nevertheless, God, without any merit of our own but only by pure grace, imputes to us the perfect righteousness of Christ when we repent and believe in him.

Scripture: Eph. 2:8-9 For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast.

Source: New City Catechism