There are no angels who minister to this earth but those who do belong or have belonged to it. (D&C 130:5)
Such a concept, while unusual to many outside the LDS tradition, finds support in ancient Jewish and Christian texts, such as the following:
Many pseudepigraphic texts (e.g., 3 Enoch) holds that the Old Testament patriarch Enoch became the angel Metatron
The Medieval Jewish text, Zohar Exodus 197a speaks of the translated Elijah as an angel among angels.
Zohar Exodus 231a says that "Gabriel is the messenger for this world, hence he had to put on the garments of this world."
Zohar Leviticus 68a-b states that “at the time when God breathed spirit into all the hosts of the heavens, they all came into being and existence, but some were held back until the Holy One, blessed be He, sent them below, and these have sway both above and below. Hence Elijah said: “As the Lord liveth before whom I have stood” (I Kings XVII, 1), not “before whom I am standing." Afterwards he returned to his place and ascended to his chamber, but the others do not ascend until they die, because they did not stand before God previously. Therefore Elijah and all those who cleave to the King were made messengers [angels] of the heavenly King, as we find in the book of Adam that all holy spirits above perform God’s messages and all come from one place, whereas the souls of the righteous are of two degrees combined higher, and therefore they ascend to a great height. This applies to Enoch and Elijah."
2 Enoch (J) 30:10-14, speaking of Adam, God is recorded as saying,
And on the earth I assigned him to be a second angel, honored and great and glorious. And I assigned him to be a king, to reign on the earth and to have my wisdom. And there was nothing comparable to him on the earth, even among my creatures that exist And I assigned to him a name from the four components:
from East - (A)
from West - (D)
from North - (A)
from South - (M)
And I assigned to him for special stars, and called his name Adam.
Other examples could be given, but it is clear that such a concept strong support.