19. Ward off the devil
The Sign of the Cross is one of the very weapons we use in that battle with the devil. As one medieval preacher named Aelfric declared, “A man may wave about wonderfully with his hands without creating any blessing unless he make the sign of the cross. But, if he do, the fiend will soon be frightened on account of the victorious token.” In another statement, attributed to St. John Chrysostom, demons are said to “fly away” at the Sign of the Cross “dreading it as a staff that they are beaten with.” (Source: Catholic Encyclopedia.)
20. Seal ourselves in the Spirit
In the New Testament, the word sphragis, mentioned above, is also sometimes translated as seal, as in 2 Corinthians 1:22, where St. Paul writes that, “the one who gives us security with you in Christ and who anointed us is God; he has also put his seal upon us and given the Spirit in our hearts as a first installment.” In making the Sign of the Cross, we are once again sealing ourselves in the Spirit, invoking His powerful intervention in our lives.
21. Witness to others
As a gesture often made in public, the Sign of the Cross is a simple way to witness our faith to others. “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,” wrote St. Cyril of Jerusalem.