The first prayer that most parents teach their children is the Sign of the Cross. This ancient gestural prayer customarily begins and ends our formal prayer, from grace before meals to the Church’s principal prayer, the Mass. According to the 1911 edition of the Catholic Encyclopedia, the ancient origin of the Sign of the Cross is unclear, but its form has evolved over time: It’s now a large gesture rather than a small one; uses three fingers instead of two, and goes from left-to-right instead of right-to-left.
What has remained largely unchanged is the meaning of the gesture. As followers of Jesus Christ, we are united to his passion death and resurrection. We take the sign of his cross on to our own bodies. This central symbol of our faith becomes the beginning point of our prayer, and its conclusion. It’s how we place boundaries in time and space that say, “Now I’m praying; this time belongs to God.” Our actual words, “In the name of the Father and of the Son and of the Holy Spirit,” reflect this delineation of sacred time and space, and recognize that all we are and all we do is connected to the mystery of the Trinity.
In addition to beginning and ending prayer, the Sign of the Cross is used at other times as well, for example, when receiving a formal blessing, receiving absolution, and entering a church and blessing oneself with holy water. Generally speaking, it’s appropriate to make the Sign of the Cross any time you hear the words, “In the name of the Father and of the Son and of the Holy Spirit.”