John 16:23 – In that day you will ask nothing of me. Truly, truly, I say to you, whatever you ask of the Father in my name, he will give it to you. Until now you have asked nothing in my name. Ask, and you will receive, that your joy may be full.

Now this gets into some difficult theology that people have debated for millennium.  What difference does prayer actually make?  Is prayer just something that makes you feel better psychologically?  Is prayer more about the inward change of the believer than outward change in the world?