Jesus is like units, such as meters (m), kilograms (kg), or seconds (s). Units connect numbers with physical things, like Jesus connects the spiritual and the physical world.
Jesus is like a good experiment. Experiments are the bridge between theory, math, and philosophy on one side, and engineering and real life applications on the other side.
Jesus is like a baby elephant. A large elephant can be groped at by blind men and never be comprehended because of its large size. But if that elephant had a baby - something begotten to be of the same elephant nature yet small enough to be felt by the blind - then they could get a good idea of the large elephant.
Jesus is like the universe. Any created thing tells us something about God, so if we look at all created things (the universe) we have a good picture of what God is like. But Jesus is the perfect image of the invisible God, in whom all fullness of the Deity dwells in bodily form.
Jesus is like nothing else. Seriously, I wrote this and the previous posts because I think I understand some things, but what am I to say about the Incarnation? I think (I'm not sure) I know enough to say that I know nearly nothing compared to the infinite mystery that is the Incarnation. I feel like a child who imagines that he "knows math" because he knows that two plus two is four. But I'm still going to keep writing those things that I do know: "The secret things belong to God, but the revealed things belong to us and our descendants forever".
You may next want to read:
For Christmas: the Incarnation
The Incarnation: Why did Jesus come into the world?
Another post, from the table of contents