"Their resemblance lies in their power as FOUNDATIONS. Their difference lies in what rests upon them. Both are cornerstones for systems of belief by which men live.
It is a mistake to believe that a thought-system which is based on lies is weak. NOTHING made by a child of God is without power. It is absolutely essential that you realize this, because otherwise you will not understand why you have so much trouble, and will be unable to escape from the prisons you have (made) for yourselves.
Man is free to believe what he chooses. What he DOES attests to what he believes." Taken from ACIM - Urtext