First of all, Jesus tells us to forgive our brother not 7 times, but 70 times 7 times.
Jesus tells us to turn the other cheek. He tells us that if someone demands our cloak we should give them our sandals also.
He tells us that unless we forgive others, we will not merit the forgiveness God gives us freely. (There is a great deal moer to this and I don’t remember it all).
He tells us we need to confess our sins to one another (in the early church people would confess their sins in public and be absolved by the early priests).
Before we go forward to offer our sacrifice to God, we need to examine ourslves to see if our brother has anything against us. If so, we need to leave our offering at the alter, become reconciled with our brother before placing our offering to the Lord. (this is one of the reasons for the “sign of peace” before communion).
Hope that helps!