First Peter 2:24 says of Jesus, “who Himself bore our sins in His own body on the tree, that we, having died to sins, might live for righteousness—by whose stripes you were healed.” This is one of at least five references or allusions the apostle makes in verses 2:22-25 to Isaiah 53, the classic Old Testament chapter predicting the suffering of the Savior. In that chapter, the emphasis of God’s prophet is on the substitutionary atonement of the coming Messiah for sin. Likewise, Peter’s use of Isaiah’s phrase “by whose stripes you were healed” is consistent. The context surrounding 1 Peter 2:24 is the healing for sin that is provided for by the work of the Sin-bearing Savior.
However, some mistakenly interpret this to refer to a promise for physical healing. Concerning the erroneous teaching that the blood of Christ guarantees the healing of illness, Greek scholar Kenneth Wuest writes the following in his Word Studies:
The Greek word translated “stripes” refers to a bloody wale trickling with blood that arises under a blow. The word is singular, not plural. Peter remembered the body of our Lord after the scourging, the flesh so dreadfully mangled that the disfigured form appeared in his eyes as one single bruise.
Thus we have the portrait of the suffering Servant of Jehovah, His blessed face so pummeled by the hard fists of the mob that it did not look like a human face anymore, His back lacerated by the Roman scourge so that it was one mass of open, raw, quivering flesh trickling with blood, His heart torn with anguish because of the bitter, caustic, malevolent words hurled at Him. On that bleeding, lacerated back was laid the Cross. Unsaved reader, this was all for you, just as if you were the only lost person in the universe. The Lord Jesus died for you, in your stead, took your place on the Cross, paid your penalty, so that God could offer a salvation from sin based upon a justice satisfied. Will you not right now appropriate the Lord Jesus as your personal Savior, trust Him to save you? And saint, does not all this make you love the Lord Jesus more, soften and make more tender your heart? Does not all this make you say, “I can see the blood drops, red ‘neath His thorny crown, from the cruel nail wounds, now they are falling down; Lord, when I would wander from thy love away, let me see those blood drops shed for me that day?” the blood of Christ heals our sin in that He by one offering put away sin forever. There is no room here for the healing of illness through the blood of Jesus. The Cross was a purely judicial matter. One goes to a hospital when one is ill, and to a law court to take care of legal matters. In the great law court of the universe, the Judge offers mercy on the basis of justice satisfied at the Cross. The matter of bodily illness is not mentioned in the context. Furthermore, the Greek word used here is not confined in its meaning to physical healing. In Luke 4:18 it refers to the alleviation of heartaches, and in Hebrews 12:13, to the rectifying of one’s conduct. In Matthew 13:15, it means, “to bring about (one’s) salvation.” This passage cannot therefore be made to teach the erroneous doctrine that healing of the body is to be found in the atonement as salvation from sin is found at the Cross. The context in which the word is found clearly decides the meaning of the word here, not that of the healing of the body, but that of the salvation of the soul.
Does God heal our physical diseases? Yes, when He chooses to do so, and sometimes miraculously. Other times; however, He employs illness for greater purposes (E.g. Paul's thorn in the flesh). But is physical healing guaranteed by Christ’s atonement? No, that is never taught in the Scriptures. Instead, what is taught is that the suffering of Jesus Christ on the cross was sufficient payment for our sins---spiritual healing which meets a need that is far more serious than relief from physical illness. Our Great Savior endured the wrath of God against sin in His body on the cross. Our hope for complete physical healing is not found in the Cross, but in the future bodily resurrection that awaits those who believe the gospel.