To have delusion is practice.  This is to attain enlightenment before you realize it.  Even though you do not realize it, you have it.  So when you say, "This is delusion," that is actually enlightenment itself.  If you try to expel the delusion it will only persist the more, and your mind will become busier and busier trying to cope with it.  This is not so good.  Just say, "Oh, this is just delusion," and do not be bothered by it.  When you just observe the delusion, you have your true mind, your calm, peaceful mind.  When you start to cope with it you will be involved in delusion.