All things were made through him, and without him was not any thing made that was made.(John 1:3, ESV)In Genesis we can read, "...God created the heavens and the earth..." In other words, everything. All the stuff up there and all the stuff down here. He made it all.
And in those creative acts that unfold in Genesis, you get these little Trinitarian glimpses. For example, we see the Spirit of God "hovering over the waters." Or when it came to the creation of man, God says, "Let us make man in our image."
In John, we are given an even deeper glimpse into the creation, and we learn that it was Jesus who created it all. This thought can steer our understanding of the rest of Jesus' earthly, physical ministry. Knowing that He made it all can give us insight into His interactions with what He has made.
We can also understand from this verse that there is a sharp line between created things and the creator. Jesus clearly falls on the side of Creator.
As you seek to know who Jesus is, remember that He is creator of all.