The Bible says love “…keeps no record of wrongs.” (1 Corinthians 13:5)
Love gives up its right to be angry and extends grace and mercy, instead. Jesus’ death on the cross is the supreme example of that. If He was willing to suffer and die for the sins I would commit against Him, then I should certainly follow His example in extending grace to others. My mind knows this, but my emotions need supernatural help to live it out. My first reaction, when offended, is to feel angry and want revenge. But with prayer, those feelings can be brought under control and God can give me His perspective on the situation and guide my response. Remembering that I’m not perfect helps me to forgive others.
To forgive means I choose to never again mention what the person did to offend me, to them or to others, (unless I have their permission to do so). I choose not to hold that offense against them.
In some cases, I may learn from experience that the person is not trustworthy and be aware of that fact, but I still choose to extend grace to them and treat them with respect.
Since I do not like people to use my past mistakes against me, I try not to do that to them. Erase the record. Start with a clean slate.