The meaning of a word or a verse is dependent upon context. Take for instance John 1:4:
"In him was life, and the life was the light of men" (John 1:4, ESV).
What does John mean by "the life was the light of men"?
Parallel with 5:26: Word/Son shares in the self-existing life of God. Later, Jesus claims that he is both the light of the world (8:12; 9:5) and the life (11:25; 14:6). Both Wisdom and the Torah are commonly associated with life and light in the Jewish sources; John ties them with Christ, the Word.
In the the remainder of the book (after 1:4), John uses life/light as it relates to salvation. The “light” is the revelation which people may receive active faith and be saved and the life is either resurrection life or spiritual life.
Here life/light are different and within the context of the first three verses, it is more likely that the life inhering in the Word is related not to salvation but to creation. The self-existing life of the Word was dispensed at creation that it became the light of men (not sure if John is referring to being created “in the image of God” or the “general revelation” found in creation). If I had to guess, since the self-existing life contained Word pertains to creation then John is referring to being created "in the image of God."