Here is the petition that is the most needed to maintain our relationship with God. It is the petition that helps to keep our mind and soul pure so that we can commune with Him in prayer. Hence this petition for daily forgiveness makes it possible to be satisfied with our daily bread, and also makes it probable that He will guide us and deliver us from evil when we ask Him.
The forgiveness that we ask for is according to our debts to God. For God has given us His laws and we have not obeyed them, we have not been righteous as He requires. Thus, because of our sin against God, we owe Him a huge debt of consequence. How can we pay this debt? It is so immense, so gigantic that we will never be able to pay it back. Therefore, all we can do is cry out to God for mercy and to ask Him to forgive us and cleanse us.
Our crying out with confession must be genuine and sincere. For that reason, this petition states that as we ask God to forgive us we must also forgive our debtors. Hence, we must have a repentant heart, a heart that has already begun to show forgiveness to others. For unless our relationship with others is right, our relationship with God will not and can not be right (Matt. 5:23-24).
Moreover, if we do not forgive others, He will not forgive us or hear our prayers (Read the story in Matthew 18:21-35, which illustrates God’s forgiveness and how we ought also to forgive others. Read also Psalms 66:18).
But the question that will eventually come up is this: How do we forgive someone whom has abused us and hurt us, and when we feel so bitter inside? To start with I suggest praying about it. Then think about how God has forgiven you (Eph. 4:32). He placed all our sins on His Son Jesus (Is. 53:6). He died and paid the penalty for our sins. And now, because our sins are paid for, He remembers them no more (Jer. 31:34). For they have all been blotted out (Is. 43:25). This is what God has given us in Christ when you placed your faith in Him.
This forgiveness I have been speaking of is positional forgiveness, a forgiveness by God toward us that guarantees our eternal salvation. But we also need relational forgiveness. This is what we must pray for every day, and what this petition is about. And if we have a repentant heart, one that is proved by our forgiveness to others, then we have the promise in 1 John 1:9—that He will forgive us and cleanse us from all unrighteousness.