“Our Father, which art in heaven, Hallowed be Thy name. Thy kingdom come. Thy will be done, as in heaven so in earth. Give us this day our daily bread. And forgive us our debts, as we forgive our debtors. And suffer us not to be led into temptation; but deliver us from evil. Amen.” ~Matthew 6:9
Cyprian (A.D. 200-258), in his treatise on the Lord’s Prayer, comments,
How great is the Lord’s indulgence! How great His condescension and plenteousness of goodness towards us, seeing that He has wished us to pray in the sight of God in such a way as to call God Father, and to call ourselves sons of God, even as Christ is the Son of God,—a name which none of us would dare to venture on in prayer, unless He Himself had allowed us thus to pray! We ought then, beloved brethren, to remember and to know, that when we call God Father, we ought to act as God’s children; so that in the measure in which we find pleasure in considering God as a Father, He might also be able to find pleasure in us. Let us converse as temples of God, that it may be plain that God dwells in us. Let not our doings be degenerate from the Spirit; so that we who have begun to be heavenly and spiritual, may consider and do nothing but spiritual and heavenly things; since the Lord God Himself has said, “Them that honour me I will honour; and he that despiseth me shall be despised.” The blessed apostle also has laid down in his epistle: “Ye are not your own; for ye are bought with a great price. Glorify and bear about God in your body.”
 Cyprian of Carthage, “On the Lord’s Prayer”, trans. Robert Ernest Wallis, in The Ante-Nicene Fathers, Volume V: Fathers of the Third Century: Hippolytus, Cyprian, Novatian, Appendix ( ed. Alexander Roberts et al.;Buffalo, NY: Christian Literature Company, 1886), 450.