Thomas Aquinas

“ Whether rivalry exists among the angels as regards their guardianship?
Art. 1 - Whether men are guarded by the angels? Objection 1: It would seem that men are not guarded by the angels. For guardians are deputed to some because they either know not how, or are not able, to guard themselves, as children and the sick. But man is able to guard himself by his free-will; and knows how by his natural knowledge of natural law. Therefore man is not guarded by an angel. ”

“ As men depart from the natural instinct of good by reason of a sinful passion, so also do they depart from the instigation of the good angels, which takes place invisibly when they enlighten man that he may do what is right. Hence that men perish is not to be imputed to the negligence of the angels but to the malice of men. ”

“ I answer that, As appears above (A [2] ) , the guardianship of the angels is an effect of Divine providence in regard to man. Now it is evident that neither man, nor anything at all, is entirely withdrawn from the providence of God: for in as far as a thing participates being, so far is it subject to the providence that extends over all being. God indeed is said to forsake man, according to the ordering of His providence, but only in so far as He allows man to suffer some defect of punishment or of fault. ”

“ Further, angels are appointed to the guardianship of men, that they may take them by the hand and guide them to eternal life, encourage them to good works, and protect them against the assaults of the demons. But men who are foreknown to damnation, never attain to eternal life. ”

“ Secondly, inasmuch as a man is part of a community, and thus one man is appointed as guardian of a whole community; to whom it belongs to provide what concerns one man in his relation to the whole community, such as external works, which are sources of strength or weakness to others. But angel guardians are given to men also as regards invisible and occult things, concerning the salvation of each one in his own regard. Hence individual angels are appointed to guard individual men. ”

“ As to what is the ordering of Divine wisdom on such matters, the angels cannot know it unless God reveal it to them: and so they need to consult Divine wisdom thereupon. Wherefore forasmuch as they consult the Divine will concerning various contrary and opposing merits, they are said to resist one another: not that their wills are in opposition, since they are all of one mind as to the fulfilment of the Divine decree; but that the things about which they seek knowledge are in opposition. ”

“ Likewise universal natural knowledge of the law, which by nature belongs to man, to a certain degree directs man to good, but not in a sufficient degree; because in the application of the universal principles of law to particular actions man happens to be deficient in many ways. Hence it is written (Wis. 9:14) : "The thoughts of mortal men are fearful, and our counsels uncertain." Thus man needs to be guarded by the angels. ”

“ Therefore universally and absolutely speaking the angels do not will sin and the pains inflicted on its account: but they do will the fulfilment of the ordering of Divine justice in this matter, in respect of which some are subjected to pains and are allowed to fall into sin. ”

“ And therefore as guardians are appointed for men who have to pass by an unsafe road, so an angel guardian is assigned to each man as long as he is a wayfarer. When, however, he arrives at the end of life he no longer has a guardian angel ”

“ Now in their actions, the angels are ruled by the Divine decree. But it happens at times in various kingdoms or various men there are contrary merits or demerits, so that one of them is subject to or placed over another. ”