“Thus the most precious treasure and strongest consolation we Christians have is this: that the Word, the true and natural Son of God, became man, with flesh and blood like that of any other human; that He became incarnate for our sakes in order that we might enter into great glory, that our flesh and blood, skin and hair, hands and feet, stomach and back might reside in heaven as God does, and in order that we might boldly defy the devil and whatever else assails us. We are convinced that all our members belong in heaven as heirs of heaven’s realm.” Martin Luther, Sermons on the Gospel of St. John: Chapters 1—4, in Luther’s Works, vol. 22, p. 110. [Emphasis added]
Dr. Luther taught that the central of the Christian message was the Incarnation, that is, the Word becoming flesh. However, Luther asserted that the Christ became a human being for the purpose of transforming the lowly bodies (and souls) of believers into something glorious. This is what Christians confess as the resurrection of the body.