Scholastic theologians augmented and ordered the taxonomy of angelic guardians.
Thomas Aquinas agreed with Honorius and believed that it was the lowest order of angels who served as guardians, and his view was most successful in popular thought, but Duns Scotus said that any angel is bound by duty and obedience to the Divine Authority to accept the mission to which that angel is assigned.
The concept of angels that guard over particular people and nationalities played a common role in Ancient Judaism, while a theory of tutelary angels and their hierarchy was extensively developed in Christianity in the 5th century by Pseudo-Dionysius the Areopagite.
The theology of angels and tutelary spirits has undergone many refinements since the 5th century.
The nature of the angel is to be, to a degree, as its name in Hebrew signifies, a messenger, to constitute a permanent contact between our world of action and the higher worlds.
An angel's missions go in two directions: it may serve as an emissary of God downward…
In Rabbinic literature, the Rabbis expressed the notion that there are indeed guardian angels appointed by God to watch over people.
Rashi on Daniel 10:7 "Our Sages of blessed memory said that although a person does not see something of which he is terrified, his guardian angel, who is in heaven, does see it; therefore, he becomes terrified." According to Rabbi Leo Trepp, in late Judaism, the belief developed that, "the people have a heavenly representative, a guardian angel. Previously the term `Malakh', angel, simply meant messenger of God." Chabad believes that people might indeed have guardian angels.
For Chabad, God watches over people and makes decisions directly with their prayers and it is in this context that the guardian angels are sent back and forth as emissaries to aid in this task.
Thus, they are not prayed to directly, but the angels are part of the workings of how the prayer and response comes about.