This is a really good question. The Old Testament tells us that when God created man from the clay of the earth He then “breathed into his nostrils the breath of life; and man became a living being” (Genesis 2:7). In the New Testament, after Christ’s Resurrection from the dead, He appeared to His disciples and “breathed on them” saying, “receive the Holy Spirit” (St. John 20:22).

Therefore, during baptism, the priest gently blows upon the child’s face in a cross-wise fashion both in remembrance of God’s creation of man in the Garden of Eden and of man’s re-creation into a New Life through Christ’s Holy Resurrection. This same basic principle also carries over to when the priest blows upon the water in the baptismal font, which is blessed and re-sanctified by the Holy Spirit “moving over the face of the waters” (Genesis 1:2).