1 In the beginning was the Word, and the Word was with God, and the Word was God.
2 The same was in the beginning with God.
3 All things were made by him; and without him was not any thing made that was made.
4 In him was life; and the life was the light of men.
5 And the light shineth in darkness; and the darkness comprehended it not. (John 1)
Origin in Stoic philosophy, intermediary between spiritual God and physical world. Rational foundation of existence.
Philo adopts idea to explain biblical anthropomorphisms (descriptions of God in human terms: speaking, being seen, etc.).
Jesus described as a manifestation of God on earth.