How do we greet a priest?

«When you come across a priest and an Angel, first you will greet the priest and then the Angel».

Clergyman. The priest, is not just anyone we meet and interact with in our daily lives.
His Priesthood. His Ministry. His Shape. His Mission.

His Presence, they set him and will or require him to be both in and out of “this world”. The religious – Christian education, the Greek Orthodox priesthood tradition,
Our culture, our history, our nobility of the soul do not allow us to address the clergyman with their stereotypical worldly greetings: “Good morning”, “Good evening”, “Good night”. Or, “Be well always”, “Have a good time”, “Bye-bye”, “See you”, exchanged between lay people.

To a clergyman at any hour of the day, whether we meet him inside or outside the Church, with a slight bow of the head downward, “By bowing down or ascending to God is done,” we humbly and reverently address the: “Bless you Father” and he, conscious of his high, holy and sacred mission, as a spiritual beacon of Christ’s Light, as a minister of the holy mysteries of the Church of the Crucified and Risen Jesus, as an Orthodox presence-witness, as a father of all, with modesty and pride answers : “The Lord“.

St. Gregory of Nazianzus calls the Priesthood “Art of Arts and Science of Sciences” and the Priest “Angel of the Lord“.
(From the Gerontikon)