If the kingdom of heaven is likened to a kingdom in this parable, then the King must be the Son of God, for He is the King of the heavens, the absolute Wisdom, the absolute Righteousness and absolute Truth. Thus, is He not so also absolute Kingdom? But it is not a kingdom of any of those below, nor of a part of those above, but of all the things above, which were called heavens.
But if you enquire into the meaning of the words, “Theirs is the kingdom of heaven,” you may say that Christ is theirs in so far as He is the absolute Kingdom, reigning in every thought of the man who is no longer under the reign of sin which reigns in the mortal body of those who have subjected themselves to it. When I say reigning in every thought, I mean reigning as Righteousness, Wisdom, Truth and the rest of the virtues in him who has become a heaven, because of bearing the image of the heavenly, and in every power, whether angelic, or the rest that are named saints, not only in this age, but also in that which is to come, and who are worthy of a kingdom of such a kind. Accordingly this kingdom of heaven (when it was made “in the likeness of sinful flesh,” that for sin it might condemn sin, when God made “Him who knew no sin to be sin on behalf of us,” who bear the body of our sin), is likened to a certain king who is understood in relation to Jesus being united to Him, if we may dare so to speak, having more capacity towards being united and becoming entirely one with the “First-born of all creation,” than he, who, being joined to the Lord, becomes one spirit with Him. Now of this kingdom of the heavens which is likened unto a certain king, according to the conception of Jesus, and is united to Him, it is said by anticipation that he wished to make a reckoning with His servants.
The Scholar Origen, Commentary on Matthew, ANF, v. 10.