A Course in Miracles Topic - Mistakes

The idea that mistakes have the power to change Truth, is part of the ego's argument that the separation is real. 
   Every “mistake” has a learning function, or else it is meaningless.

The Son of God can be mistaken ... There is nothing he can do that would really change his reality in any way, nor make him really guilty.    T-19.II.3:1-3.

It is essential that error be not confused with sin, and it is this distinction that makes salvation possible. For error can be corrected, and the wrong made right. ... Sin is the proclamation that... guilt is justified.                           T-19.II.1:1,2,/2:3.

An error ... is not attractive. What you see clearly as a mistake you want corrected.    T-19.III.3:1,2. 

Mistakes are for correction, and they call for nothing else. What calls for punishment must call for nothing. Every mistake must be a call for love. T-19.III.4:5-7.