James 5:16b The prayer of a righteous person is powerful and effective.
If I were asked to give one reason for adding fasting to my prayer it would be that it makes my prayer more effective. It’s not that I believe that God will give me more, but that the will of God will be more accepted in the lives of myself and the people around me. I know it sounds crazy but sometimes people have to be convinced that His will is always a good thing. Until they accept that, they will never allow His will to happen. Fasting increases the effectiveness of prayer.