Pray The Lord’s Prayer. Keep praying. When
you get to the point where you refer to those who
trespass against you, you should specifically
mention the name of the person who offended
you. It is important to specifically mention the
name of that person.
So the prayer becomes for example, “...And
forgive me for my trespasses, as I forgive
Person X.” In other words, “If I have not
forgiven Person X for their sins against me,
please do not forgive me!!!”
If you are able to pray like that, asking God to
forgive you specifically in relation to your
forgiveness of certain people in your life, it is
very likely that you have forgiven them.