Some good Bible verses about forgiveness are Isaiah 55:7, Luke 17:3, and Ephesians 1:7. These verses discuss,respectively, three different types of forgiveness: the forgiveness of humans by God, forgiveness of one another, and the "ultimate" forgiveness given to man through Jesus Christ's death on the cross.
The Bible verse Isaiah 55:7 details the forgiveness God has for humans: "Let the wicked forsake their ways and the unrighteous their thoughts. Let them turn to the Lord, and he will have mercy on them, and to our God, for he will freely pardon."
Luke 17:3 discusses the importance of forgiveness between fellow men. It reads, "So watch yourselves. If your brother or sister sins against you, rebuke them; and if they repent, forgive them."
A Bible verse about the "ultimate" forgiveness is Ephesians 1:7. Jesus Christ died on the cross for the so that man's sins would always be forgiven. This verse states, "In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God's grace."