This admirable summary of prayer, as introduced by Matthew, would seem to be only for the purpose of illustrating, by example, the foregoing precepts. Luke, however, represents it as occasioned by our Saviour’s being engaged in prayer at a certain place, and when he ceased, one of his disciples saying unto him, “Lord, teach us to pray, as John also taught his disciples.” If in any thing we need Divine instruction, it is in drawing near to God. It does not appear to have been Christ’s design to establish a form of prayer, nor that it was ever so used by the disciples; but merely a brief directory as to the matter and manner of it. Such a directory was adapted not only to instruct, but to encourage Christians in their approaches to God. It was putting words into their mouths. In supplicating Divine mercy, they might plead, Thus and thus our Saviour taught us to say; even he in whom thy soul delighteth: hear us for his sake! Observe,

First, The character under which we are allowed to draw near to the Lord of heaven and earth.—“Our Father.” It has been a question, though I conceive it ought not, whether God is here to be considered as our Father in Jesus Christ, and not rather as our Creator; and whether the prayer be not suited to all men, who are God’s creatures, as well as to believers. That the prayer is free to every one who can cordially utter its sentiments there is no doubt; but whatever others have done, Christ would never prescribe a prayer suited to an unbeliever. As the Scriptures inculcate no precept but what, if obeyed in its true intent, would prove us in the way to eternal life, so they prescribe no prayer but what, if offered up in its true meaning, would be heard and answered. It is true that God is the Father of all men by creation; but, like prodigals, they are by sin alienated from him, and his love to them as a Creator is in a manner extinguished. He cannot consistently treat them as children, but as stangers and enemies. If strict justice had its course, he would “destroy man, whom he hath created, from the face of the earth.” The effect is, that if any of the sons of men approach him as a Father, it must be through a Mediator. The original relation is, as to any access to him, or communion with him, dissolved. If any sinner be now treated as a child of God, it is as an adopted alien put among the children.—See John 1:13.

It is no small proof that the privilege of approaching God as a Father has respect to the mediation of Christ, that it is almost confined to the gospel dispensation. To Israel, it is true, pertained the national adoption; but this was only a shadow of that to which believers were predestinated through Jesus Christ. Old Testament believers were no doubt related to God as a Father, as well as we; but they were not ordinarily in the habit of addressing him under that endearing character. The spirit of that dispensation was, when compared with ours, a spirit of bondage. It was reserved for the times of the Messiah, in the spirit of adoption, to cry, Abba, Father. The encouragement contained in this tender appellation is inexpressible. The love, the care, the pity, which it comprehends, and the filial confidence which it inspires, must, if we are not wanting to ourselves, render prayer a most blessed exercise.

Secondly, The place of the Divine residence.—“Our Father, who art in heaven.” As the endearing character of a father inspires us with confidence, this must have no less a tendency to excite our reverence; and both together are necessary to acceptable worship. “As for me, I will come into thy house in the multitude of thy mercy; and in thy fear will I worship toward thy holy temple.” Fear without hope would sink us into despair; and hope without fear would raise us to presumption; but united together, they constitute the beauty of holiness. It is not, however, for the purpose of inspiring reverence only that God is said to be in heaven, but to encourage us to confide in his absolute supremacy and almighty power. He is above all our enemies, and has the direction and control of all events. What can be more consoling than the thought of having the Lord of the universe for our Father! When the heathen triumphed over the church, and sneeringly asked each other, “Where is now their God?” it was sufficient to answer, “Our God is in the heavens, he hath done whatsoever he hath pleased.”

Fuller, A. G. (1988). “The Lord’s Prayer,” Illustrations of Scripture, The Complete Works of Andrew Fuller: Memoirs, Sermons, Etc. (J. Belcher, Ed.; Vol. 1, pp. 577–579). Sprinkle Publications.