Throughout history, the right hand has been traditionally used for blessing or whenever one makes the sign of the cross, probably due in part to the fact that most people are right-handed. Yet scripturally, there is a precedent connected to the right, both culturally and spiritually. For instance, in the parable of the Last Judgment (Matt. 25:31-46), Jesus places the sheep on His right hand but the goats on His left. When our Lord is arrested and brought before the High Priest and asked if He is the Messiah, Jesus says, “I am; and you will see the Son of man seated at the right hand of Power” (Mark 14:62). The Psalms also mention the “right hand of God” as do numerous passages in the Book of Acts. Even our most ancient iconography depicts Jesus raising his right hand in blessing. This is because in the Bible, to be at the right side is to be identified as being in the special place of honor. Perhaps this is why we continue to use our right hand when shacking hands or giving a military salute.
By contrast, the left hand has, in many cultures, a very different set of traditional associations. For example, the left hand is often designated for personal hygiene. This is why in Middle Eastern cultures where everyone shares food from a common bowl, one only uses the right hand to eat with. In fact, the word sinister is actually derived from the Latin term for left-handed. Therefore, for all these reasons, it is natural that the sign of the cross has traditionally been made using the right hand.
