Why do we have the pope?
Yes, Christians must fast. In Matthew 6:16, Jesus said, "And when you fast, be not as the hypocrites, sad." He did not say, "If you fast" or "If you would like to fast." Thus, as Christians, we are obliged and are expected by God to fast. Moreover, not just fasting, but praying and almsgiving as well (Mt. vi. 2, 5).