Powerful scripture.
"And whenever you stand praying, forgive, if you have anything against anyone , so that your Father also who is in heaven may forgive you your trespasses.”
Mark 11:25
"But if you do not forgive others their trespasses, neither will your Father forgive your trespasses."
Matthew 6:15
What else does the Bible say about forgiveness? https://www.openbible.info/topics/forgiveness