Quote from ACIM Text Chapter 6, Section 4 - The Relinquishment of Attack.

Since you cannot not teach, your salvation lies in teaching the exact opposite of everything the ego believes. This is how you will learn the truth that will set you free, and will keep you free as others learn it of you. The only way to have peace is to teach peace. By teaching peace you must learn it yourself, because you cannot teach what you still dissociate. Only thus can you win back the knowledge that you threw away. An idea that you share you must have. It awakens in your mind through the conviction of teaching it. Everything you teach you are learning. Teach only love, and learn that love is yours and you are love.