In N.T.Wright’s book, Surprised by Hope (p. 128), he notes that the Greek word parousia “is usually translated “coming,” but literally it means “presence”-that is, presence as opposed to absence.” He goes on to discuss two meanings of the word in non-Christian contexts which would have influenced the Christian understanding (page 129):
The first meaning was the mysterious presence of a god or divinity, particularly when the power of this god was revealed in healing. People would suddenly be aware of a supernatural and powerful presence, and the obvious word for this was parousia. Josephus sometimes uses this word when he is talking about YHWH coming to the rescue of Israel. God’s powerful, saving presence is revealed in action, for instance when Israel under King Hezekiah was miraculously defended against the Assyrians.
The second meaning emerges when a person of high rank makes a visit to a subject state, particularly when a king or emperor visits a colony or province. The word for such a visit is royal presence: in Greek, parousia. In neither setting, we note, obviously but importantly, is there the slightest suggestion of anybody flying around on a cloud. Nor is there any hint of the imminent collapse or destruction of the space-time universe.
Wright then applies this meaning to the Parousia of Christ, saying that the Early Christians believed that while Jesus was present in spirit, he was absent in body, and they waited for Christ to come in body and make his powerful presence known to the everyone. Secondly, the Early Christians were evidently proclaiming that Jesus was the true Emperor of the world, who would soon rule not in absence but in person, and that Caesar was a “sham”.