One simple answer is that He wants us to experience freedom, not the chains of anxiety and roots of bitterness that bind us when we don’t forgive. It’s FOR US, not for the person who offended us or did us wrong. His heart is for us to experience the authentic life that He created for us fully. If our heart is filled with anger or bitterness, there’s not much room for Holy Spirit.
But more importantly, it’s because Jesus forgave us!
Matthew 18:21-25 provides a clear picture of how God views unforgiveness and bitterness, and the consequences we will suffer if we choose not to forgive.
In verses 32-34, the master called in the unmerciful servant and said, ‘You wicked servant,’ he said, ‘I canceled all that debt of yours because you begged me to. Shouldn’t you have had mercy on your fellow servant just as I had on you?’ In anger, his master handed him over to the jailers to be tortured until he should pay back all he owed.