There are many reasons. However, those that stand out most powerfully are learning to think clearly, and to dispel ignorance, fantasy, greed, hatred and craving. This is the road to a place where one must lose all clinging to self.
Whenever you meditate you explain what you blessed, for as a picture in your mind, or by listening the words in your conscious mind. Consequently are going to step into your subconscious mind for processing. Doing it this way routinely it is going to come easier every time you do.
For Further Read: Why Should I Meditate?