From St. Cyprian’s Treatise on Prayer
Above all, the Teacher of peace and Master of unity did not want prayer to be made singly and privately, so that whoever prayed would pray for himself alone. We do not say My Father, who art in heaven or Give me this day my daily bread; nor does each one ask that only his own debt should be forgiven him; nor does he request for himself alone that he may not be led into temptation but delivered from evil. Our prayer is public and common, and when we pray, we pray not for one person but for the whole people, since we, the whole people, are one.
The God of peace and the Master of concord, who taught unity, willed that one should pray for all, just as he himself, being one, carried us all. The three children observed this law when they were shut into the fiery furnace, praying with one voice and with one heart: thus our faith in divine Scripture teaches us, and, as it teaches us how such people prayed, gives us an example that we should follow in our own prayers, so that we may become like them: Then these three sang a hymn as if with one mouth, and blessed the Lord. They spoke as if with one mouth, even though Christ had not yet taught them how to pray.
And therefore, as they prayed, their prayers were heard and were fruitful, because a peaceful, sincere, and spiritual prayer deserved well from the Lord. Thus, too, we find the Apostles and the disciples praying after the ascension of the Lord: They all continued with one accord in prayer, with the women and with Mary who was the mother of Jesus, and his brothers. They continued with one accord in prayer, showing, by the urgency and the unanimity of their praying, that God, who makes the inhabitants of a house to be of one mind, only admits to his divine and eternal home those among whom prayer is unanimous.
But, dear brethren – what deep blessings are contained in the Lord’s prayer! How many they are, and how great, collected in so few words but so rich in spiritual power! There is nothing at all that is not to be found in these our prayers and petitions, as it were a compendium of heavenly doctrine. Thus, he said, you must pray: Our Father, who art in heaven.
The new man, re-born and brought back to God by his grace, says Father at the very beginning, for he has just begun to be God’s son. He came to his own, and his own did not accept him. But to those who did accept him he gave power to become children of God, to those who believe in his name. Whoever believes in God’s name and has become his son, should start here so that he can give thanks and profess himself to be God’s son, by calling God his Father in heaven.