Quote from ACIM Text Chapter 4, Section 2 - Right Teaching and Right Learning.

I will substitute for your ego if you wish, but never for your spirit. A father can safely leave a child with an elder brother who has shown himself responsible, but this involves no confusion about the child's origin. The brother can protect the child's body and his ego, but he does not confuse himself with the father because he does this. I can be entrusted with your body and your ego only because this enables you not to be concerned with them, and lets me teach you their unimportance. I could not understand their importance to you if I had not once been tempted to believe in them myself. Let us undertake to learn this lesson together so we can be free of them together. I need devoted teachers who share my aim of healing the mind. Spirit is far beyond the need of your protection or mine. Remember this:

In this world you need not have tribulation because I have overcome the world. That is why you should be of good cheer.