To teach your disciple how to love is to teach your disciple how to forgive. I have nothing close to a photographic memory except when I am hurt, rejected, or wronged. (I wish I could remember the Bible half as clearly as I do the wrongs done to me.) There are many things that I have forgotten from my childhood but my hurts and disappointments are etched in my heart as if in stone. These memories are so powerful that they can even overshadow all the good that has been done for me.
People keep a running ledger of those they feel “owe me an apology” and yet Paul tells us that “Love keeps no record of wrongs” 1 Corinthians 13:5. Your disciple will learn how to release others from his ledger by experiencing God’s forgiveness in the cross of Jesus and then through your example of forgiving him and forgiving others.
There will be times that your disciple will take a couple of steps backwards which may surprise and disappoint you. During his failure it is easy for both you and him to focus on the two steps of regress. One way to help him understand forgiveness is to focus on the step of progress rather than on the two steps back. Often his experience has been people holding his failure and sin over his head to use them as leverage.