In addition to serving as a vehicle for the prayer of beings composed of body and spirit, the postures and gestures in which we engage at Mass have another very important function. The Church sees in these common postures and gestures both a symbol of the unity of those who have come together to worship and a means of fostering that unity. We are not free to change these postures to suit our own individual piety, for the Church makes it clear that our unity of posture and gesture is an expression of our participation in the one Body formed by the baptized with Christ, our head. When we stand, kneel, sit, bow and sign ourselves in common action, we given unambiguous witness that we are indeed the Body of Christ, united in heart, mind and spirit. Each posture we assume at Mass underlines and reinforces the meaning of the action in which we are taking part at that moment in our worship.

The fundamental posture in liturgy is standing. Standing is a natural gesture of respect toward authority. Indeed, standing was the normal position for Jewish prayer and this custom passed to Christianity as is witnessed by murals in the catacombs. Standing is a sign of respect and honour. This posture, from the earliest days of the Church, has been understood as the stance of those who are risen with Christ and seek the things that are above. When we stand for prayer we assume our full stature before God, not in pride, but in humble gratitude for the marvellous thing God has done in creating and redeeming each one of us. By Baptism we have been given a share in the life of God, and the posture of standing is an acknowledgment of this wonderful gift.

The faithful should stand from the beginning of the Entrance chant, or while the priest approaches the altar, until the end of the Collect. We stand as the celebrant who represents Christ enters and leaves the assembly.

For the Alleluia chant before the Gospel; while the Gospel itself is proclaimed. We stand for the proclamation of the Gospel, which recounts the words and deeds of the Lord. During the Profession of Faith and the Prayer of the Faithful; from the invitation, before the prayer over the offerings until the end of Mass.

Today the faithful mostly remain standing whenever they are associated to the solemn prayer of the celebrant. The upright position is that of the heavenly elect as seen in the Book of Revelation 7:9 and 15:2. The Fathers of the Church considered this position as expressive of the holy freedom of God's children. St. Basil in his treatise on the Holy Spirit says that "We pray standing, on the first day of the week, but we do not all know the reason. On the day of the resurrection (or 'standing again'; Greek anastasis) we remind ourselves of the grace given to us by standing at prayer, not only because we rose with Christ, and are bound to 'seek those things which are above,' but because the day seems to us to be in some sense an image of the age which we expect …" (Chapter 27).