Have you ever looked out on the world in all its vastness, seen the many trees and rocks and animals, and just wondered, “Why is any of this here?”
It may seem like a bit of a trippy question, but it’s an interesting one. Why is there something rather than nothing? The universe could have just as easily been an infinite void of space without any matter. Theologically speaking, God did not have to create anything; as a relationship of Father, Son, and Spirit, God is a perfect community of love and so did not need anything else.
And yet, quite obviously, God did create something. And not only did God create, but God became a part of that creation.
Why?
I imagine that many are able to answer the second question with some confidence, that Jesus came to be like us to save us from our sins, but this doesn’t help us to answer the first question. There must be a different reason…
Breaking In The Habit 
This is the best explanation of the incarnation I’ve ever heard. Non-christians have an issue sometimes wondering why God put the serpent in the Garden of Eden to tempt in the first place. This is a better answer because God didn’t make them sin, but he knew they would be curious. Being a deeper part of us, being inside us, providing an experience of the Trinity which is God in wholeness rather than just the Father, is more interesting that just walking beside us in the garden.