Sin must be punished. The Gospel tells us how God can save sinners by grace, and still be holy in doing so. Christ suffered the wrath and judgment of God against sin. On the basis of the work of Christ, God can forgive the sins of those who trust the Lord Jesus. Christ has finished the work.
Grace only demands faith on the part of the sinner who seeks salvation.
This means that a true believer can enter into God's presence by prayer. He is no longer separated from God by his sins.