"Forgive us our trespasses as we forgive those who trespass against us"
Yes, this is a tough one. How much more would our flesh like God to zap our offenders with fire and brimstone? However, we must forgive others if we want God to forgive us. A lot of times I pray in this manner: "Lord Y'hoshua, help me to forgive others as You forgave from the cross." Here are some scriptures that show us how important it is for us to forgive others as God has forgiven us.
Ye have heard that it hath been said, Thou shalt love they neighbor, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. For if ye love them which love you, what reward have ye? Do not even the publicans the same? And if ye salute your brethren only, what do ye more than others? Do not even the publicans so? Be ye therefore perfect, even as your Father which is in heaven is perfect. Matthew 5:43-48
Therefore is the kingdom of heaven likened unto a certain king, which would take account of his servants. And when he had begun to reckon, one was brought unto him, which owed him ten thousand talents. But forasmuch as he had not to pay, his lord commanded him to be sold, and his wife, and children, and all that he had, and payment to be made. The servant therefore fell down and worshipped him, saying Lord, have patience with me, and I will pay thee all. Then the lord of that servant was moved with compassion, and loosed him, and forgave him the debt. But the same servant went out, and found one of his fellow servants, which owed him an hundred pence: and laid hands on him and took him by the throat, saying, Pay me that thou owest. And his fellow-servant fell down at his feet, and besought him, saying, Have patience with me, and I will pay thee all. And he would not: but went and cast him into prison, till he should pay the debt. So when his fellow servants saw what was done, they were very sorry, and came and told unto their lord all that was done. Then his lord, after that he had called him, said unto him, O thou wicked servant, I forgave thee all that debt, because thou begged me: Shouldest not thou also have had compassion on thy fellow servant, even as I had pity on thee? And his lord was wroth, and delivered him to the tormentors, till he should pay all that was due unto him. So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses. Matthew 18:23-35
For if ye forgive men their trespasses, your heavenly Father will also forgive you: But if ye forgive not men their trespasses, neither will your Father forgive your trespasses. Matthew 6:14, 15