The Fifty Miracle Principles of A Course in Miracles
by Kenneth Wapnick
 

Principle 16

Miracles are teaching devices for demonstrating it is as blessed to give as to receive. 
They simultaneously increase the strength of the giver and supply strength to the receiver.

This is the same idea as Principle 9. You can see that a lot of the principles now are going to repeat themselves. Just as with time, the miracle is a teaching device, and the idea is to help us realize that we are not separate.

The miracle teaches us that "to give and to receive are one in truth," which by the way, is the title of workbook lesson 108. We are all the same: teacher and pupil; therapist and patient; the one who heals and the one who is healed. Remember that the error that the miracle has to correct is the error of believing we are separate. The miracle, then, becomes an expression of our joining, and that is what this principle is talking about.