Reply Obj. 1: Those who are unbaptized, though not actually in the Church, are in the Church potentially. And this potentiality is rooted in two things—first and principally, in the power of Christ, which is sufficient for the salvation of the whole human race; secondly, in free-will.
Reply Obj. 2: To be "a glorious Church not having spot or wrinkle" is the ultimate end to which we are brought by the Passion of Christ. Hence this will be in heaven, and not on earth, in which "if we say we have no sin, we deceive ourselves," as is written (1 John 1:8). Nevertheless, there are some, viz. mortal, sins from which they are free who are members of Christ by the actual union of charity; but such as are tainted with these sins are not members of Christ actually, but potentially; except, perhaps, imperfectly, by formless faith, which unites to God, relatively but not simply, viz. so that man partake of the life of grace. For, as is written (James 2:20): "Faith without works is dead." Yet such as these receive from Christ a certain vital act, i.e. to believe, as if a lifeless limb were moved by a man to some extent.
Reply Obj. 3: The holy Fathers made use of the legal sacraments, not as realities, but as images and shadows of what was to come. Now it is the same motion to an image as image, and to the reality, as is clear from the Philosopher (De Memor. et Remin. ii). Hence the ancient Fathers, by observing the legal sacraments, were borne to Christ by the same faith and love whereby we also are borne to Him, and hence the ancient Fathers belong to the same Church as we. _______________________
FOURTH ARTICLE [III, Q. 8, Art. 4]
Whether Christ Is the Head of the Angels?
Objection 1: It would seem that Christ as man is not the head of the angels. For the head and members are of one nature. But Christ as man is not of the same nature with the angels, but only with men, since, as is written (Heb. 2:16): "For nowhere doth He take hold of the angels, but of the seed of Abraham He taketh hold." Therefore Christ as man is not the head of the angels.
Obj. 2: Further, Christ is the head of such as belong to the Church, which is His Body, as is written (Eph. 1:23). But the angels do not belong to the Church. For the Church is the congregation of the faithful: and in the angels there is no faith, for they do not "walk by faith" but "by sight," otherwise they would be "absent from the Lord," as the Apostle argues (2 Cor. 5:6, 7). Therefore Christ as man is not head of the angels.
Obj. 3: Further, Augustine says (Tract. xix; xxiii in Joan.), that as "the Word" which "was in the beginning with the Father" quickens souls, so the "Word made flesh" quickens bodies, which angels lack. But the Word made flesh is Christ as man. Therefore Christ as man does not give life to angels, and hence as man He is not the head of the angels.
On the contrary, The Apostle says (Col. 2:10), "Who is the head of all Principality and Power," and the same reason holds good with the other orders of angels. Therefore Christ is the Head of the angels.
I answer that, As was said above (A. 1, ad 2), where there is one body we must allow that there is one head. Now a multitude ordained to one end, with distinct acts and duties, may be metaphorically called one body. But it is manifest that both men and angels are ordained to one end, which is the glory of the Divine fruition. Hence the mystical body of the Church consists not only of men but of angels. Now of all this multitude Christ is the Head, since He is nearer God, and shares His gifts more fully, not only than man, but even than angels; and of His influence not only men but even angels partake, since it is written (Eph. 1:20-22): that God the Father set "Him," namely Christ, "on His right hand in the heavenly places, above all Principality and Power and Virtue and Dominion and every name that is named not only in this world, but also in that which is to come. And He hath subjected all things under His feet." Therefore Christ is not only the Head of men, but of angels. Hence we read (Matt. 4:11) that "angels came and ministered to Him."