Trinity & Divinity, Part 2 - John 1:1-4

John 1:1 In the beginning was the Word, and the Word was with God, and the Word was fully God.
In the beginning of time - a created thing - the Word already existed; the Word is eternal. The Word was with God in the beginning. The Word's nature is fully God (this translation reflects the Greek grammatical construction of that last clause).

John 1:2 The Word was with God in the beginning.
Reiterates the Word being eternal.

John 1:3 All things were created by him, and apart from him not one thing was created that has been created.
The Word created everything, without exception.

John 1:4 In him was life, and the life was the light of mankind.
Life is part of the Word's nature, not something given to or created in the Word. This is only true of God.

In all likelihood, John was writing here to respond to and to differentiate the teachings of gnosticism from Christian teaching. Gnosticism held a dualistic view of spirit (= good) and matter (= evil). This set up for them a paradox ... how could God (= spirit = good) have created matter (= evil)? The solution was a hierarchical series of emanations descending from God which were progressively less perfectly good (or wise), until finally a sufficiently less than perfectly good (or wise) divine being was imagined that would create matter. John would have none of that! John made explicitly clear that the Word was there in the beginning (not some first-created being), that the Word was fully God, and that nothing was created without the Word having created it. John laid a clear wall, dividing Christianity from gnosticism (and other teachings that deny the Deity of the Word, Jesus).