All things were made by him; and without him was not any thing made that was made. – John 1:3
All creation owes its existence to Jesus Christ Who was the One who spoke everything into being. Paul confirms this position when he told the Colossians:
For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him: And he is before all things, and by him all things consist. – Col. 1:16-17
John gospel also shows us that Jesus is the specific source of life for men as well.
In him was life; and the life was the light of men. – John 1:4
That was the true Light, which lighteth every man that cometh into the world. – John 1:9
John uses the terms life and light interchangeably and shows that, not only does all creation owe its existence to Jesus, all mankind in particular receives life from Jesus. This life is different than the life that is in plants, fish and animals. When we look at the Genesis record, we see that the creation of man was last and it was strikingly different. The animals were all created and instantly alive while man was made from the dust as an inanimate being. God then breathed into man the breath of life and man became a living soul. John is saying that this breath was given by Jesus. This breath is the eternal nature that all mankind has.
The living soul of man is different than the soul of beasts. When an animal dies it ceases to exist. When men die, their souls go back to God (Ecclesiastes 3:21). The children of God inherit everlasting joy and the wicked receive everlasting torment. Either way, the soul of man continues on after corporeal death. So in this sense, Jesus is the source of life for all humans.