"Is anyone among you sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord.
And the prayer of faith will save the sick, and the Lord will raise him up.
And if he has committed sins, he will be forgiven."
James 5:14,15
"Ask in faith, with no doubting, for he who doubts is like a wave of the sea driven and tossed by the wind.
For let not that man suppose that he will receive anything from the Lord."
James 1:6,7
Prayer for healing is not about overcoming God's unwillingness, because God is not at all unwilling to heal.
Prayer for healing is about laying hold of God's willingness to heal.
It's about applying the provision He has already made for healing in the work of Jesus.
Ask in faith.
The Bible says that the prayer of faith will save the sick, that is, make them well.
The prayer of faith is not about begging God.
Begging is doubting God's desire to heal.
Believing is taking God at His Word.
Do not waver between praying and begging for what God has already promised.
Begging and doubting have no guarantee of receiving anything from God, but God's Word affirms that the prayer of faith will heal the sick.