13 And lest the soul should stray and linger in some delusion of heathen philosophy, it receives this further lesson of perfect loyalty to the holy faith, taught by the Apostle in words inspired:— Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the word, and not after Christ; for in Him dwells all the fullness of the Godhead bodily, and you are made full in Him, Which is the Head of all principality and power; in Whom you were also circumcised with a circumcision not made with hands, in putting off the body, of the flesh, but with the circumcision of Christ; buried with Him in Baptism, wherein also you have risen again through faith in the working of God, Who raised Him from the dead.
And you, when you were dead in sins and in the uncircumcision of your flesh, He has quickened with Him, having forgiven you all your sins, blotting out the bond which was against us by its ordinances, which was contrary to us; and He has taken it out of the way, nailing it to the Cross; and having put off the flesh He made a show of powers openly, triumphing over them through confidence in Himself. Steadfast faith rejects the vain subtleties of philosophic enquiry; truth refuses to be vanquished by these treacherous devices of human folly, and enslaved by falsehood.
It will not confine God within the limits which barred our common reason, nor judge after the rudiments of the world concerning Christ, in Whom dwells all the fullness of the Godhead bodily, and in such wise that the utmost efforts of the earthly mind to comprehend Him are baffled by that immeasurable Eternity and Omnipotence. My soul judged of Him as One Who, drawing us upward to partake of His own Divine nature, has loosened henceforth the bond of bodily observances Who, unlike the Symbolic Law, has initiated us into no rites of mutilating the flesh, but Whose purpose is that our spirit, circumcised from vice, should purify all the natural faculties of the body by abstinence from sin, that we being buried with His Death in Baptism may return to the life of eternity (since regeneration to life is death to the former life), and dying to our sins be born again to immortality, that even as He abandoned His immortality to die for us, so should we awaken from death to immortality with Him.
For He took upon Him the flesh in which we have sinned that by wearing our flesh He might forgive sins; a flesh which He shares with us by wearing it, not by sinning in it. He blotted out through death the sentence of death, that by a new creation of our race in Himself He might sweep away the penalty appointed by the former Law. He let them nail Him to the cross that He might nail to the curse of the cross and abolish all the curses to which the world is condemned. He suffered as man to the utmost that He might put powers to shame.
For Scripture had foretold that He Who is God should die; that the victory and triumph of them that trust in Him lay in the fact that He, Who is immortal and cannot be overcome by death, was to die that mortals might gain eternity. These deeds of God, wrought in a manner beyond our comprehension, cannot, I repeat, be understood by our natural faculties, for the work of the Infinite and Eternal can only be grasped by an infinite intelligence. Hence, just as the truths that God became man, that the Immortal died that the Eternal was buried, do not belong to the rational order but are an unique work of power, so on the other hand it is an effect not of intellect but of omnipotence that He Who is man is also God, that He Who died is immortal, that He Who was buried is eternal.
We, then, are raised together by God in Christ through His death. But, since in Christ there is the fullness of the Godhead, we have herein a revelation of God the Father joining to raise us in Him Who died; and we must confess that Christ Jesus is none other than God in all the fullness of the Deity.
Source: On the Trinity (New Advent)