The Holy Book of Tobit (5:12) makes Archangel Raphael sound like a liar for taking on the name "Azarias," and the kinship to Tobit. Could you please explain?
In the story of Tobias and the Angel, God sent the Angel Raphael to guide Tobias to collect a debt in a distant country. We are not specifically told why Raphael did not disclose his identity until the end of the journey. Perhaps it has to do with the teachings of Tobias's father "Seek the advice of the wise man," "Pray to God at all times and let Him direct your ways," and also to get to know if Tobias, when tested, would obey these teachings. The angel gave Tobias a set of instructions all of which he obeyed in the order they were delivered in. The Angel instructed Tobias to: catch a fish, make a medicine out of the fish’s heart, gall, and liver, and to take a wife at a relative of Tobias'. Furthermore when the Angel told Tobias to apply the medicine on the eyes of his father he did so. Following this act of obedience, Archangel Raphael, disclosed his identity to Tobit and Tobias.
Concealed identity is not confined to this Biblical case alone. Another example is the three strangers who visited Abraam (God and 2 angels). Our beloved saints' stories narrate that Anba Bishoy did not know the elderly man whom he had carried up the mountain was the Lord.
I encourage you to continue your reading in the Holy Bible; always keeping in mind the theme of the story, its context and setting.