A Course in Miracles teaches that “there is no world”. God is…and nothing else is. (Level 1) This is the metaphysical level.
However, there is a “belief” in the world. A Course in Miracles is a course in cause (the mind) and not effect ( the whole universe of time & space which includes the body as the central figure in the dream of the world).
The Course teaches us how to “look” at the world (with the mind) while we believe we are here having an experience in the made-up holographic time-space dream. The Course gives us a practical approach to how we live in the world. (Level 2) On this level, the Holy Spirit’s orJesus’ perception/thought system is the truth and the ego’s perception/ thought system is the illusion.
A “gentler dream” where we forgive ourselves, others and our seeming problems precedes our awakening to Spirit. Practicing the Holy Spirit’s/Jesus’ thought system leads to the experience of what the Course calls the “happy dreams of forgiveness”. This is still part of the illusion and still only in the mind. However, choosing the Holy Spirit’s or Jesus’ interpretation of the dream ( happy dreams of forgiveness) leads us away from error ( the choice for the ego’s thought system of separation – sin, guilt, and fear) and towards awakening to who we are and where we never really left – our Oneness w/God.