10 Nor ought we, beloved brethren, only to observe and understand that we should call Him Father who is in heaven; but we add to it, and say our Father, that is, the Father of those who believe— of those who, being sanctified by Him, and restored by the nativity of spiritual grace, have begun to be sons of God. A word this, moreover, which rebukes and condemns the Jews, who not only unbelievingly despised Christ, who had been announced to them by the prophets, and sent first to them, but also cruelly put Him to death; and these cannot now call God their Father, since the Lord confounds and confutes them, saying, “You are born of your father the devil, and the lusts of your father you will do.
For he was a murderer from the beginning, and abode not in the truth, because there is no truth in him.” And by Isaiah the prophet God cries in wrath, “I have begotten and brought up children; but they have despised me. The ox knows his owner, and the ass his master's crib; but Israel has not known me, and my people has not understood me. Ah sinful nation, a people laden with sins, a wicked seed, corrupt children! You have forsaken the Lord; you have provoked the Holy One of Israel to anger.” In repudiation of these, we Christians, when we pray, say Our Father; because He has begun to be ours, and has ceased to be the Father of the jews, who have forsaken Him.
Nor can a sinful people be a son; but the name of sons is attributed to those to whom remission of sins is granted, and to them immortality is promised anew, in the words of our Lord Himself: “Whosoever commits sin is the servant of sin. And the servant abides not in the house for ever, but the son abides ever.”
Source: The Treatises of Cyprian (New Advent)