I mentioned yesterday in the morning sermon the ancient Christian tradition of making the sign of the cross. This tradition, practiced by Catholics, Orthodox and some protestants as well, has ancient roots. Tertullian mentions it as early as the second century, and in the fourth century Cyril of Jerusalem instructed converts to make the sign of the cross.
Let us not then be ashamed to confess the Crucified. Be the Cross our seal made with boldness by our fingers on our brow, and on everything; over the bread we eat, and the cups we drink; in our comings in, and goings out; before our sleep, when we lie down and when we rise up; when we are in the way, and when we are still. Great is that preservative; it is without price, for the sake of the poor; without toil, for the sick; since also its grace is from God. It is the Sign of the faithful, and the dread of devils: for He triumphed over them in it, having made a shew of them openly (Col. ii. 15); for when they see the Cross they are reminded of the Crucified; they are afraid of Him, who bruised the heads of the dragon. Ps. lxxiv. 13.. Despise not the Seal, because of the freeness of the gift; out for this the rather honour thy Benefactor (from section 36 Lecture XII, "On the Words Crucified and Buried").
Cyril makes a good point regarding the centrality of the cross for the Christian. Sins are forgiven and Satan is defeated because of Christ's work on the cross. He makes a mistake, however, when he says that that power can be invoked by making the sign of the cross. My point yesterday was that the power of the cross belongs to us by faith in Jesus Christ, not by making the sign of the cross or by doing any other religious rituals (for Protestants such acts of ritualistic devotion may take other forms, as I also noted yesterday).
In John 12:36 Jesus says, "While you have the light, believe in the light, that you may become sons of light.” To believe is to have faith--the root is the same Greek. So, Jesus emphasizes faith in Himself as the light of the world (John 8:12). Paul emphasizes faith in Christ as well. In Romans he writes, "For there is no distinction: for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith" (Romans 3:22-25). When Paul says that God put Christ forward as a "propitiation by his blood" he is speaking about the crucifixion. A propitiation was a sacrifice offered to avert wrath. God's wrath on sinners is placed on Jesus on the cross. All who receive Christ by faith receive this this benefit from his crucifixion. This cross work of Christ received by faith, is the basis for our salvation. So Paul writes in Ephesians, "For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast" (Ephesians 2:8-9).
The forgiveness of sins and freedom from spiritual darkness purchased by Christ on the cross is ours by faith in Him. Sadly, for many people the sign of the cross has become a ritual, rather than something that bolsters real faith in Christ. For those who think that they are accessing Christ's power through making this sign, it has actually become a deadly substitute for faith that saves and sanctifies. Certainly, if one thinks that by making this sign one can be forgiven, scare demons, receive some special blessing, or bring about a substantial change in the elements used in the Lord's Supper then one has departed from the teaching of Jesus and Paul.
We should learn from the early fathers and from the traditions of the church, but we must always to Scripture to regulate our faith and our practice. Not one time does the New Testament tell believers to make the sign of the cross. Christ and his benefits are ours by faith alone.