The 1985 Extraordinary Synod of Bishops asserted “that the liturgy must favor the sense of the sacred and make it shine forth. It must be permeated by the spirit of reverence, adoration, and the glory of God." To foster such a spirit, the Church has prescribed certain gestures and actions, especially toward the Blessed Sacrament.
The practice of genuflecting before the Blessed Sacrament, whether enclosed in the tabernacle or exposed in a monstrance, is a beautiful sign of adoration. This physical act of genuflection symbolizes our heart bowing before the Lord who is substantially and really present in the Eucharist. St. Ambrose (d. 397) said, “The knee is made flexible by which the offense of the Lord is mitigated, wrath appeased, grace called forth," and Alcuin (d. 804) later added, “By such a posture of the body we show forth our humbleness of heart."
Following the same line of thought, kneeling also holds a special place in fostering a proper reverence. Going back to our Lord’s time, the Jewish people often stood while praying; however, when the occasion was solemn, the petition urgent, or the prayer was offered with great fervor, then the person humbly knelt before his God to pray. For instance, when Jesus prayed in the Garden of Gethsemane, the gospel reads, He “went down on His knees and prayed…" (Luke 22:41).
Concerning the Eucharistic Prayer of the Mass, the General Instruction on the Roman Missal stipulated that the congregation stand during the Eucharistic Prayer except for the consecration. As a matter of fact, the General Instruction only specified kneeling during the consecration (#21), which accounts for the observed difference in some other countries. However, the Holy See extended permission to local Bishops’ Conferences to adapt gestures and postures to meet the sensibilities of their own people as long as the meaning and purpose of the part of the Mass were not diminished. Therefore, in 1969, the National Conference of Catholic Bishops decided to retain for parishes in America the practice of the congregation kneeling through the entire Eucharistic Prayer, after the recitation of the Sanctus until after the Amen. Moreover, we kneel after the Agnus Dei until the time to receive Holy Communion, and most people kneel out of reverence while they make an act of thanksgiving after receiving Holy Communion. To me, this practice of kneeling seems most appropriate during the Eucharistic Prayer of the Mass, for “in this divine sacrifice which is celebrated in the Mass, the same Christ who offered Himself once in a bloody manner on the altar of the cross is contained and is offered in an unbloody manner" (Council of Trent).
Concerning the reception of Holy Communion, the Sacred Congregation for Sacraments and Divine Worship in Inaestimabile donum (1980) permitted the faithful to receive Holy Communion either kneeling or standing according to the norms established by the local Bishops’ Conference. In each diocese, kneeling or standing to receive Holy Communion is established by parish custom.
Some confusion arises concerning whether it is proper to genuflect before receiving Holy Communion. The Sacred Congregation for Sacraments and Divine Worship did state, “When the faithful communicate kneeling, no other sign of reverence towards the Blessed Sacrament is required, since kneeling is itself a sign of adoration. When they receive Communion standing, it is strongly recommended that, coming up in procession, they should make a sign of reverence before receiving the Sacrament. This should be done at the right time and place, so that the order of people going to and from Communion is not disrupted" (General Instruction, #11). This “strong recommendation" seems most appropriate for those places that do not kneel during Mass except for the consecration; in those cases, the faithful would practice a common gesture of genuflection or bowing. However, given that in the United States Catholics kneel during the entire Eucharistic Prayer and also after the Lamb of God until the time of receiving Holy Communion, this practice of genuflection or bowing has not been mandated.
These regulations help unify the worship of a congregation as well as foster in the individual both a proper reverence while participating at Mass and devotion toward the Blessed Sacrament. The General Instruction asserted, “A bodily posture common to all who are present is a sign of their unity with each other as a congregation; it expresses the mental attitude and dispositions of those taking part and enhances them" (#20).