Faithlessness - Words used in A Course in Miracles

Faithlessness would always limit and attack; faith would remove all limitations and make whole. Faithlessness would destroy and separate; faith would unite and heal. Faithlessness would interpose illusions between the Son of God and his Creator; faith would remove all obstacles that seem to rise between them. … Both cannot be together, nor perceived in the same place.    T-19.I.5:3-5,9.

Faithlessness brought to faith will never interfere with truth. But faithlessness used against truth will always destroy faith. ...   Only what you have not given can be lacking in any situation.    T-17.VII.3:9,10/4:1.

Faithlessness is the servant of illusion, and wholly faithful to its master. Use it, and it will carry you straight to illusions.  ... Accept not the illusion of peace it offers, but look upon its offering and recognize it is illusion.      T-17.VII.5:5,6,9.

The goal of illusion is as closely tied to faithlessness as faith to truth. If you lack faith in anyone to fulfill, and perfectly, his part in any situation dedicated in advance to truth, your dedication is divided. And so you have been faithless to your brother, and used your faithlessness against him.    T-17.VII.6:1-3.

You do not use anything your brother has done before to condemn him now. You freely choose to overlook his errors, looking past all barriers between yourself and him, and seeing them as one. And in that one you see your faith is fully justified. There is no justification for faithlessness, but faith is always justified.    T-19.I.9:4-7.