Illusionism is the belief that the “world” only appears to be real. Our senses deceive us. The mind or spirit is the guide to true reality. It solves the problem of evil by denying its existence. It affirms God and denies evil, whereas atheism affirms evil and denies God. Theism affirms the reality of both but denies that there is a contradiction. This belief has been around for ages, but in the West you can find this teaching in Christian Science. God is truth and there is no pain in truth and truth in pain. Sin, sickness, and death therefore are mortal illusions that do not exist in reality.

If you view your sin as an illusion and not reality, why would you ask Jesus for forgiveness? 

Cited Sources: Baker Encyclopdia of Christian Apologetics by Norman Geisler