Whether Angels can be considered Saints
Objection 1. It would seem that angels cannot be numbered among the Saints because during the Holy Sacrifice of the Mass, the one presiding says:
...all the Angels and Saints
and furthermore, at benediction the one presiding says (and the people respond):
blessed be God in His Angels and in His Saints
So these would seem to be two separate groups of people
Objection 2. Further, the Holy Church has shown throughout Salvation History that she only canonizes those who have died in the Grace of God. Angels have no capacity for death and therefore cannot be canonized as such.
Objection 3. Further, Holy Mother Church makes a distinction between those whom she knows, through objective means (posthumous miracles) or through her own power of binding and loosing (as is the case with Bl. Pope John XXIII) or by right of dying specifically for Christ (martyrdom) wherein one does not have the ability to recant the grace freely given and makes their death the sacrifice beyond which there is no greater love.
On the Contrary the Catholic Church, which apparently is the arbiter of who is numbered among the Saints, has consistently referred to the angels as Saints. Mor Gabriel Monestary is one of the oldest surviving Churches in the world, dedicated to St. Gabriel.
I answer that, the term saint is a qualifier used to mean holy but a canonized Saint is an office, as is Angel. Angel is a job title meaning messenger of God. Just as a person can be both a computer programmer and a father, one can be an Angel and a Saint.
Reply to Objection 1 the words used in the sacred liturgies, whereas they are unsurpassed in beauty and reverence, are not, in and of themselves, theological treatises. Therefore, if you hear Jesus referred to as thrice Holy, that isn't to say He isn't also holy four times over as well.
Reply to Objection 2 It is true that the relatively recently established norms of canonization are more or less ignored when it comes to Biblical figures, when it comes to those who do not need the grace of Christ's redemption to save them from death, the Ox
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.
and so he lumps us all together in Heaven where Christ is the Head and we all (the Church) are His Body. And so, a thing that separates us from the Angels (the ability to die) does not separate us from becoming Saints any more than it separates Angels from being Saints.
Reply to Objection 3. Lastly, the Church, through Holy Scripture knows which of the Angels clung to the true light (The Trinity) or the false light (Lucifer) because those who clung to the truth are the heroes of the Bible. St. Raphael aids Tobias on his journey and saves him, his future wife's honor and his father. St. Michael wrested from Lucifer the body of Moses and preserved the holy man from scorn. St. Gabriel, best of all, announced the birth of Christ to Mary. But, to even accomplish this task, they must have gotten their orders from God Himself and therefore "merited beatitude" as the Ox
...ultimate beatitude exceeds both the angelic and the human nature. It remains, then, that both man and angel merited their beatitude.