By Archbishop Michael Jackels
To celebrate Holy Mass, the priest walks to the sanctuary, that part of the church where the altar is. He bows to the altar and then kisses it. If the tabernacle is behind the altar, the priest might instead genuflect (from the Latin: to bend the knee).
The bow is a sign of reverence to a sacred object, like the altar, which represents Christ. It is also an expression of humility, of recognizing who we are before God.
Kissing is also a sign of reverence. Where Jesus lived, kissing on one or both cheeks is a form of greeting. For the same reason, whoever reads the Gospel kisses the book.
Genuflecting is a sign of adoration to Jesus, who we believe is substantially present in the Eucharist, which is reserved in the tabernacle. Speaking of bowing, the priest also bows his head slightly at the mention of the names of Trinity, Jesus, Mary, and the saint of the day – again, as a sign of reverence.
And during the Profession of Faith, the whole congregation bows at the waist as a sign of reverence for God becoming man, born of the Virgin Mary.