It looks like the NT author was referring to
Philo's take on the Logos:
Philo (20 BCE – 50 CE), a Hellenized Jew, used the term Logos to mean an intermediary divine being, or
demiurge.
[7] Philo followed the Platonic distinction between
imperfect matter and perfect Form, and therefore intermediary beings were necessary to bridge the enormous gap between God and the material world.
[34] The Logos was the highest of these intermediary beings, and was called by Philo "the first-born of God."
[34] Philo also wrote that "the Logos of the living God is the bond of everything, holding all things together and binding all the parts, and prevents them from being dissolved and separated."
[35]
Plato's Theory of Forms was located within the Logos, but the Logos also acted on behalf of God in the physical world.
[34] In particular, the
Angel of the Lord in the
Hebrew Bible (
Old Testament) was identified with the Logos by Philo, who also said that the Logos was God's instrument in the creation of the universe.
[34]