James 1:5-8:

If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him.
But let him ask in faith, nothing wavering.  For he that wavereth is like a wave of the sea driven with the wind and tossed.
For let not that man think that he shall receive any thing of the Lord.
A double minded man is unstable in all his ways.

Notes on James 1:5-8:

This passage proves that you cannot successfully pray for healing saying, “If it be thy will....”  If you are saying IF, you are in doubt and you will receive nothing.  Rather than thinking that God in His sovereignty will either say “Yes” or “No” to your prayer, you must realize that you cannot receive anything from the Lord when you pray like that.  If you want something from God, you must ask in faith without wavering.  If you’re wondering, “I prayed, but where’s my healing?” you are wavering and you will not get healed.  If you really believed that you received when you prayed, as Jesus told us to do, you would never ask, “Where is it?”  You would say, “I know where it is – I have it even though I don’t see it yet!"

See also:

Your Body Is God’s Property
Do You Really Believe in Healing?
Mistaken Prayer Mindsets
Prayers God Won’t Answer
How to Tell If You’re in Faith or Not
Why You Might Not Want to Pray to Receive Your Healing Right Away
The Prayer of Nothing
Can I Believe to Become Smarter?
What Is the Difference Between Unbelief and Doubt?
Do I Have the Authority to Cast Out Computer Viruses?
Objection: We Had 24/7 Prayer Asking God to Heal So-and-So, and He Chose Not to Do It
Objection: Faith Is Simply Trust in God, Not a Force That You Use to Change Things Yourself
Objection: James Did Not Teach That Healing Was in the Atonement in His Instructions
Objection: Only Some People Have the “Gift of Faith” to Believe for Healing
Objection: Like Any Loving Parent, God Sometimes Has to Tell His Children NO for Their Own Good
Objection: Sometimes God Says, “Yes,” Sometimes He Says, “No,” and Sometimes He Says, “Wait” When You Ask for Healing
Objection: Jesus Said to Say, “Thy Will Be Done,” Instead of Demanding Healing
Objection: “If It Be Your Will” Must Always Be Implied – If You Could Literally Ask for ANYTHING, You Could Ask to Become God
Mistake: Spiritual Laziness
Mistake: Doublemindedness