Galatians 5:16:

This I say then, Walk in the Spirit, and ye shall not fulfill the lust of the flesh.

See also:

The Flesh Freakout Factor
Healing and Effort
What Romans 8:11 Really Means
Casting Out the Spirit of Stupidity
The Insecure Preacher
Healing and Repentance
Beating Ministerial Jealousy and Insecurity
How to Be Baptized with the Holy Spirit
I’m Sick Because I’m Fat!  Can I Claim Healing?
Can I Believe for “Supernatural Weight Loss?”
What Does God Think About Taking Vitamins, Immune System Enhancers, Diet Aids, and So On?
How Can I Get God to Use Me in Gifts of Healings?
Don’t Believe These Alcoholics Anonymous Lies
Can I Get Healed of Alcoholism, Drug Abuse, Pornography and Homosexuality?
Should I Go to a Hypnotist to Get Free from Habits?
Objection: Bodily Suffering Helps You Avoid Sin (1 Peter 4:1)
Objection: Groaning as Our Outward Man Perishes Is Part of This Life (2 Corinthians 4:16-5:4)
Objection: Divine Healing Teaching is Gnosticism Because It Presumes Special Secret Knowledge Is Needed to Be Healed
Objection: Romans 8 Doesn’t Talk About Healing, so Romans 8:11 Is About Strengthening Us Against Sin
Objection: Jesus Said It Is Better to Enter Heaven with One Eye or Hand Than to Go to Hell
Mistake: Carnality