2 Corinthians 1:20:

For all the promises of God in him are yea, and in him Amen, unto the glory of God by us.

See also:

Who You Are and What You Have
Healing and God’s Glory
To What Extent Can We Claim Old Testament Healing Promises?
Objection: God’s Healing Covenant in the Law of Moses Was Only for the Jews
Objection: The Curse of the Law Was Given to Israel, Not to Us.  We Cannot Be Redeemed from It Because We Were Never Under It
Objection: Mark 16:18 Does Not Say, “They Shall Recover IF They Have Enough Faith,” Yet Faith Healers Blame the Sick for Not Believing
Objection: You Lost All Your “Rights” the Day You Accepted Christ
Notes on Ephesians 6:1-3