Ephesians 1:13

In whom you....were sealed, &c. Having been regenerated in baptism, you have received the Holy Spirit and the supernatural gifts which he communicates, by which he has, as it were, impressed upon you the seal of your sanctification and the pledge of your salvation. It is not an external impression, such as that by which soldiers are marked by their sovereigns, nor circumcision, as of old, but it is a mark within you --- the grace with which you are filled --- which shews itself outwardly by miraculous effects, &c. (Calmet) --- Some refer these words, in whom you were sealed, to the sacrament of baptism; others to confirmation: both, with the sacrament of holy orders, confer a character, or mark, of which St. Paul seems to speak whenever he speaks of God sealing us.