Allusion of Illusion ?

Allusion and illusion are two different words but like an illusion can be confusing. Allusions are used to add depth and meaning to things (i.e. scriptures from the Bible), while illusions are used to describe something that appears to be one way but is actually something else. This is seen when one compares the physical world to the spiritual. Christians love allusions, while worldly men love illusions. Illusions are often related to visual perception, what one is thinking and feeling.