This aspect of the our model prayer is synonymous with the apostle John's famous injunction in I John 1:9; 'if we confess our sins, He is faithful and just to forgive us [ our ] sins and to cleanse us from all unrighteousness.' Israel had sinned, and needed to be forgiven before She could live again in God's Presence! As with all aspects of this prayer, we must consider the historical and covenantal aspects of Jesus' words here, if we are to glean a correct understanding of it's meaning!
In modern usage and understanding, as with the previous phrase, it is right & good to ask these things! However, as with the previous phrase, we must understand the significance that Jesus' words would have stirred up in the minds of His original audience, bringing to their remembrance that Israel had sinned and died. Before She could be resurrected, as promised, She had to be forgiven; thus, Jesus instructed them to pray in this manner!
Unlike the previous phrase ( 'give us this day' ), 'forgive us our sins' was of greater significance to that generation! Yes, we as Christians fail to uphold the Law of Love as we should, every day, but our sins have been forgiven! We should instead, in constant Communication & Communion with our Heavenly Father, thank Him for this forgiveness!
Israel, under that first covenant, had partaken in the sin of Adam, and thus died, so it was for this sin that Israel needed to be forgiven! As the New, or True Israel of God, the disciples of Christ were given this model for prayer to bring to their daily remembrance this damning fact. Through this realization, the disciples, representative of the Israel of God, repented of, and were forgiven for the sin of Adam!
As we thank our Heavenly Father in constant Communion & Communication with Him, let us always remember that the sins of His People have been forgiven!
Let us live our Lives in an attitude of Thankfulness as we Eat, Pray, & Love in and for His Kingdom & Glory!
Charles Haddon Shank