It is if: We have decisions to make. Acts 13:2 While they were worshiping the Lord and fasting, the Holy Spirit said, "Set apart for me Barnabus and Saul for the work to which I have called them."
It is if: We desire to hear from God. Acts 10:30 And Cornelius said, "Four days ago I was fasting until this hour; and at the ninth hour I prayed in my house, and, behold, a man stood before me, in bright clothing."Acts 10:31 And said, "Cornelius, your prayer is heard, and your alms are held in Remembrance in the sight of God."
PRAYER adds POWER to FAITH, so FASTING adds POWER to PRAYER.