Sign of the Cross

The Sign of the Cross is the most fundamental gesture-prayer of Christian life. Tracing a cross over the body while invoking the Trinity derives from Matthew 28:19 ("baptize them in the name of the Father and of the Son and of the Holy Spirit"). Tertullian (c. 200) in De Corona describes early Christians marking their foreheads with the cross in all daily actions. The current form — touching the forehead, chest, left shoulder, and right shoulder — developed in the Western Church by the medieval period; the Eastern Church uses the reverse order for the shoulders. St. Cyril of Jerusalem's catecheses (c. 350) instruct: "Let us not then be ashamed to confess the Crucified... make the sign of the cross boldly upon thy forehead." The prayer is listed first in the Compendium of the Catechism of the Catholic Church (2005), Appendix A.