1) Memorizing scripture makes meditation of scripture possible when you are not actively engaged in reading the Bible.  In other words, memorizing scripture allows us to constantly be thinking of scripture, God's written will.  By doing so, we can much more actively incorporate it into our daily lives.

2) Memorizing scripture strengthens our faith "because faith comes from hearing and hearing from the Word of God." [John Piper] 

3) Memorizing scripture changes the way that we view the world.  Having scripture in our minds enables our perspective to be more like God's. 

4) Memorizing scripture allows us to conquer temptation and sin more easily.  It is impossible for us to combat the devil and his ways without God's power that we find in scripture. 

5) Memorizing scripture guards our minds - It makes it easier for us to detect error in the world. 

6) Memorizing scripture protects us and allows us to combat the devil readily. We cannot rely on our own power in spiritual struggle (warfare). 

7) Memorizing scripture allows us to minister more effectively to those in need.  Biblical words are the most potent words that can be spoken from our mouths. 

8) Memorizing scripture gives us the model for fellowship with Jesus Christ.  Scripture is absolutely vital to having a relationship with Christ, so why wouldn't we take the time to memorize it?