“Baptism is just a sign”
Admittedly, everything I have said assumes that Baptism is more than just an outward expression of an inward acceptance of Christ. Of course, baptism is an outward expression, in that physical hands are laid on a physical person, and that the rites of the baptism are tangible, visible, and physical. But remember just how seriously the Orthodox embrace the incarnation of Christ. For us, Christ’s body was not an outward expression merely. To be sure, we cannot remain at the level of Christ’s physical body, but we must remember that His body was not an incidental part of His saving Incarnation. His body was indivisibly part of His whole person. So important in fact is the body to God that having assumed a physical existence He raised it as well, and the Christian promise is that we will be raised with our bodies. Nothing then is just an outward sign of a more important inward reality. If we insist that baptism be an external formality, then baptizing children is not necessary.
In practice, however, even among those for whom it is just a sign, a child is often clearly excluded from the common rites of the larger body of baptized believers. The fear among some of baptism effecting a change in one’s status with God, of being more than a mere sign, seems inconsistent, as Peter Leithart has pointed out, with views held by most Christians about marriage. Few Christians of any stripe would say that a marriage ceremony is merely a ‘sign’. A change clearly occurs. They are separate before the ceremony, but they are ‘one flesh’ after. This is a profound change, one which is effected by God through the ceremony itself. Baptism is no different. The rite of baptism has always been understood as a baptism into the death and resurrection of Christ, an entrance into the saving covenant, an enrollment in the Lamb’s book of life, a union with the whole people of God, and the giving of a new citizenship in the Kingdom not of this world. Clearly, this is more than just a formality.