Romans 8:13:

For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live.

See also:

Don’t Believe These Alcoholics Anonymous Lies
Can I Get Healed of Alcoholism, Drug Abuse, Pornography and Homosexuality?
What Does God Think About Taking Vitamins, Immune System Enhancers, Diet Aids, and So On?
Should I Go to a Hypnotist to Get Free from Habits?
Objection: Healing Cannot Be in the Atonement Because Healing Can Be Lost, but Salvation Cannot Be Lost
Objection: Bodily Suffering Helps You Avoid Sin (1 Peter 4:1)
Mistake: Carnality