The belief in separation, which you are working to undo through forgiveness, does not just heal your own mind.
What is it that you have been separated from? It is yourself, it is God, and it is your brother.
When you undo separation in what you think of as "your mind", the boundaries which confined your mind are expanded. Separation was COMING BETWEEN you and others. It was defining you as "not them".
Separation is an artificial wall which seems to make people into isolated individuals, with private minds experiencing private worlds.
When separation is lifted, you are literally going to become ONE with other people. They are you. They are other parts of you which you have been separated from. You, and what appeared before to be "others", in fact SHARE A MIND as the One Son of God.
You are NOT just working on your own private spiritual path in isolation. If you are truly making progress to undo separation, you are undoing the separation BETWEEN you and other people. This means it is IMPOSSIBLE to make progress in spiritual awakening without INCLUDING more and more of what it was you thought was "other people", which is actually parts of yourself that you previously were separate from. Your spiritual awakening is everyone's spiritual awakening.
That which kept you feeling isolated, imprisoned, alone, separate and in the dark, was essentially FEAR, which when it is lifted, *reconnects you* with other people. You begin to see them AS YOURSELF. And you begin to treat them how you would be treated.
In the ego's thought system, what applies to you does not apply to others. This is because it sees each individual as an isolated separated identity, cut off and kept apart. In the Holy Spirit's thought system, what applies to you applies to everyone equally, because they ARE YOU. You, and your brother, are PART OF the One Son of God. ONE identity. ONE mind. ONE Self.
Therefore as you are removing blocks to awareness of love, you are removing artificial limitations placed on "who you are", which put you in a little box and labelled you as separate. As these blocks are lifted, you will come to LOVE yourself more, and LOVE other people more. This love will JOIN and CONNECT you to other minds.
Separated minds produce sickness. Joined minds produce healing. You must set your brother free from his prison by rejoining with him as one. You must stop demonstrating sickness so as to stop accusing BOTH of you of sin. You must be the example of the love that applies to BOTH of you. It is literally in your own best interests to do this, because they ARE ONE WITH YOU!
Separation is a two-edged sword. It doesn't just apply in isolation. It causes isolation. It comes between brothers and makes them strangers. It makes a shared mind split and kept apart. When separation has gone, your mind will be SHARED with the Son of God. You are OPENING UP to a much larger sense of IDENTITY than who you thought you were, limited to a separate self, stuck in a body, or confused with that which dies.
You are EVERTHING. You are bigger than the universe. You are the Kindgom of God!