The answer
When the faithful receive the Eucharist (or the mystery of the altar), they are obliged to offer the sacrifice of repentance, love, prayer, fasting, alms, and so on, through the worthiness of the blood of Christ. Thus, they share in the mystery of the visible altar through their own mystical and hidden altars. This is also apparent from Origen’s response to Celsus when he said, “He does not perceive that we regard the spirit of every good man as an altar from which arises an incense which is truly and spiritually sweet-smelling, namely, the prayers ascending from a pure conscience. Therefore it is said by John in the Revelation, ‘The odors are the prayers of saints;’ (Rev. 5:8) and by the Psalmist, ‘Let my prayer come up before Thee as incense.’ (Ps. 141:2)”1210
St. Clement of Alexandria says, “The altar, then, that is with us here, the terrestrial one, is the congregation of those who devote themselves to prayers, having as it were one common voice and one mind.”1211
Fr. Tadros Yacoub Malaty
Notes
1210 Origen, Against Celsus 8.17 (ANF 4:646).
1211 St. Clement of Alexandria, The Stromata, or Miscellanies 7.6 (ANF 2:531).