The kingdom here desired is not that of nature, over which God necessarily exercises supreme authority and an absolute independence, as the Creator and Master of the universe. Nobody can wrest this kingdom from Him, nor weaken it, nor share it with Him, nor disturb it, nor suspend its movements in the slightest degree. We are subject to it like all other creatures; and we could not escape from it, whatever desire we might have to do so, or whatever effort we might make. This petition of the Lord's Prayer concerns the moral kingdom in which God rules over our wills, but only with our consent; to which we are entirely free to submit, although we have no right to resist, and which never extends beyond our obedience. This kingdom is glorious for God, because there is nothing forced on our part: it is the result of our own free choice.
God proposes that we should accept Him for our King; He invites us, He urges us, He even commands us; and He adds to this rewards and threats: but He uses no compulsion Indeed, what would be the use of constraint, when it is a question of winning the heart, in which violence can do nothing, and which is always master, as is proved by saying I will, or I will not have God to reign over me? It is doubtless supremely just that God should rule over His children. The love they owe Him imposes upon them the law of submission and implicit obedience; and this law can neither be hard nor oppressive to the true children of God. On the contrary, they ought to consider it their glory and their happiness to observe it, and perform cheerfully all the sacrifices it may demand. Besides, the law of God has nothing in its object to which it is not for our interest to submit, it being entirely for our advantage; and He exercises it with so much gentleness, so much wisdom, so much regard for our liberty, that He renders it infinitely agreeable.
I say to God every day, "Thy kingdom come." If these are not vain words uttered by the lips alone, without the heart taking any part in them, it is evident that I thereby pledge myself to let Him reign supremely over me; also desiring that He may reign over others, to contribute to that end as far as lies in my power, according to my state and condition in life. Let us see if I fulfill these duties. Does God reign over my spirit? Does He govern all my thoughts? Does He regulate all my opinions? In every emergency do I follow the Spirit of God? Or is it not rather my own spirit to which I listen? Have I no regard to what the world thinks, though I know it to be contrary to the thought of God? If I do not pass lightly over this examination, I shall find much in my life to reform. Saint Paul said, "As many as are led by the Spirit of God, they are the sons of God." So those who are led by any other spirit are not among His children. That sentence of the apostle, which is absolute, and admits neither exception nor restriction, contains a solemn warning. Shall I say, in order to re-assure myself, that I follow the leading of the Spirit of God in all essential things, and that I follow my own spirit and that of the world in all matters of less consequence?
It is obvious then, that in these last things I do not conduct myself as a child of God, and in this respect am unworthy of the title. It is then no less obvious, that in following either the spirit of the world or my own spirit in matters which appear non-essential, I am liable to follow them also in things of moment, and to go far astray from the Spirit of God. Let us come to the facts. What are those things which I allow myself to judge according to the ideas df the world and to my own ideas, and not according to the Spirit of God? The world and my own spirit reject all the maxims of the gospel, dictated by the Spirit of God, concerning detachment from the riches, the greatness, and the pleasures of the world; concerning self-renunciation, and the necessity of bearing one's cross; concerning the love of God and one's neighbor, even if it were possible, to the extinction of self-love; concerning meekness, patience, humility, purity of intention; concerning the lust of the flesh, the lust of the eyes, and the pride of life. Dare I say, that on all these and on other points, I judge according to the Spirit of God, without regard to my own judgment or to that of the world? Dare I say that any one of these points is of little consequence to the Christian, and that he may safely judge of it otherwise than God judges? Dare I assert, as to any one of these points, what is essential and what is not, and draw the precise limits where, without endangering my salvation, I may differ from God's judgment, and may follow my own opinions and those of the world? Even among those who have embraced a life of devotion, there are unhappily many who do not permit God to reign in their hearts without hindrance; to regulate their thoughts and their conduct in matters of religion. If they were directed only by the Spirit of God, false and imperfect devotions would not be so common. They would pray more from the heart than the lips; they would be more earnest in reforming the interior than in composing the exterior; in being docile, rather than obstinate and opinionated; in allowing themselves to be judged by those who direct them, rather than preferring to judge themselves, and perhaps judging their directors; in concealing their good works, rather than proclaiming them; in bending their character to grace, rather than in accommodating grace to their character: in short, for this detail would be infinite, they would be careful to examine, condemn, and correct themselves, rather than to observe, censure, and reform others; they would embrace a more just, more noble, more extended idea of Christian perfection; they would waste nothing in minutiae, littleness, and scruples, either in undue severity or indulgence, and all sorts of compromises with nature. The kingdom of God established in our hearts will not permit us to change our plan of action, and pass continually from one method to another: it will maintain in us a uniformity, an equanimity of temper, a peace and spiritual joy, that nothing can change or disturb. Does God reign over my heart? Is He the master of its movements and its affections? Is it He who excites them, who moderates them, who directs them? Do I apply myself under His direction, to purify myself as much as possible from the leaven of self-love, that enemy of all charity, and even of the legitimate and true love that I owe to myself? It is principally by my earnestness in discovering self-love, so skilful in disguising itself; by my courage in attacking it, and my ardor in pursuing it; by my determination to spare it in nothing, that I can decide whether the kingdom of God is established in my heart. Although I may have no criminal affections, yet have I no dangerous ones? Have I none that are vain and useless? Have I none that are excessive, however legitimate? Have I none purely natural, which it is my duty to sanctify, and which God would most assuredly sanctify if He governed me?
The principal study of the Christian should be his own heart; but is he capable of it if he is not enlightened by divine light? And does God communicate this light abundantly, at all times, to all objects, even the most delicate and imperceptible, for any but those over whom He reigns absolutely? The principal thing about which the Christian should occupy himself is the reformation of his heart; but will he have the will to undertake it, and the strength to accomplish it, if God does not constantly supply him with both these at his need? To whom does He grant this, in a measure sufficient for the consummation of this great work, except to those who have given themselves to Him, that He may reign over them, and make them after His own heart? The success of this work depends doubtless upon ourselves, but it depends much more upon God; and He works upon it with affection and distinguished care, only in favor of those who oppose no wilful resistance. Oh, what a difference in purity of heart there is between him who has made God the Master of his liberty, and him who pretends to dispose of himself in certain things, and up to a certain point, which he cannot fix, and which if he could fix, it would be very difficult, not to say impossible to hold! Let God once reign over the heart and will, and He will not delay to reign over the whole being. All will obey Him. Nothing will resist Him. He will easily triumph over the opposition of a corrupt nature, of passions and habits even the most inveterate. What order, what harmony, what holiness, in the interior and exterior life of a Christian whom God governs entirely! Though it is supernatural grace which prompts him, yet he is so easy, so uniform, so unaffected, that he always appears perfectly natural. And this is what I ask of God, for His glory and my sanctification, when I say, "Thy kingdom come." Have I realized the fulness of this petition? Is it sincere on my part? No: if I do not give myself to God without reserve, I do not wish its entire accomplishment. His dominion over me must be the result of my free and entire will; and I seem often to submit against my will, as to a painful yoke, that I shake off as much as I can. It should be unlimited, and I contract it: I limit it in a thousand things where I wish to preserve some right over myself. I do not offer this petition for myself alone. I must offer it for all Christians and for all men. I must desire that the kingdom of God may extend everywhere; that there may be no reasonable being on earth who is not submissive to it; that true religion, with its dogmas and its morals, may be known, embraced, and practised in all the coming centuries, in every country, with all the perfection it demands, and of which men are capable, in a word, that the universe may be an assembly of saints, depending for every thing upon grace; and I ought to do every thing in my power, according to my condition, my talents, and the circumstances in which I am placed by Providence, for the establishment of this kingdom. It is to this end that all authority should be exercised; that of a sovereign over his subjects, of a magistrate over those submitted to his charge, of a father over his children, of a master over his servants, of an instructor over the youths confided to him. To establish the kingdom of God in the soul, is especially the object of the ministrations of priests; and they ought to be entirely devoted to it. It becomes me then, to see what are my obligations in this respect; how I fulfill them; in what I have not performed them, and in what I have performed them badly; and to think with fear of the rigorous account I shall have to render at the great day. Our Father has promised that I shall reign with Him forever in heaven, if I allow Him to reign over me below, and over others in all that depends upon me. Jesus Christ, seated on the throne of His Father, has promised to share it with me. He says, "To him that overcometh, will I grant to sit with Me in My throne." His word is pledged to it. This reign of God, and of the elect with God in eternity, is the great object in which this petition of the Lord's Prayer terminates. It is the kingdom to which, for the glory of God and for my own happiness, I must aspire with all my might, carefully fulfilling the condition which assures me the enjoyment of it, and despising the wealth, the grandeur, and the pleasures of earth, which are nothing in comparison to it.
- from The Christian Sanctified by the Lord's Prayer, by Father Jean Nicolas Grou