The flesh and the Spirit are in constant war; if the flesh wins (making you to commit sin), ulitmately, the devil wins. -Galatians 5:17
A major way of subduing the flesh is by fasting often (you must fast to remain in the light of Christ)
The dispensation of grace entails fasting; according to Jesus' directive. -Matthew 9:14-14 (Even Paul, Apostle of Grace fasted often -2 Corinthians 9:24-27
“Set apart some days for fasting and praying; make it your lifestyle.”
Memorise:
This I say then, walk in the Spirit, and ye shall not fulfil the lust of the flesh. Galatians 5:16