"things too marvelous for me"

You can find plenty of ways of parsing out what a human is: body/mind/soul, body/soul/spirit, body/spirit, and so on. Set aside the materialist "body-only" as obviously wrong. The bottom line seems to me to be that there's something blended in a way we don't understand well. We can tell there are material and supermaterial/supernatural aspects, united into something different from either alone. We have no good words to describe this "everyday incarnation." It shouldn't surprise use that we have problems understanding the Great Incarnation. Or the Trinity.

But we try.

Incarnation is one of the deep mysteries of creation. I think one can even say it is one of the principles of creation

If that's true, there are clearly different levels of incarnation.

At one extreme take the simplest case: God creates a universe with certain rules and parameters and calls it good.

A human creator puts time and thought and purpose into the things he makes. In the care he gives those things you can see some love as well--"willing the good of another"--in this case in giving a thing existence and worth, which are good things.

If we assume that God's creating is like that in its own inimitable way, we see that God puts some of His wisdom and love (and glory, per Paul) into His creation. Since God is simple, these attributes are not different from Him, and so He in expressing Himself in creation is present in, and at some simple level united with, His creation.

That sounds almost pantheistic, but isn't--God is immeasurably beyond all creation, and only the faintest image of His glory is there, and this uniting is not as profound as other forms.

Imagine a sunset, and then imagine what you would have if God withdrew His attributes. Beauty and glory and purpose gone--no color or shape or significance (day to night). Wisdom and rule gone--no physical laws, just dark chaos. Existence gone--nothing, which we cannot even imagine, since an observer or imagine-er is something.

At the other extreme of incarnation we have Jesus--unimaginably God and Man and incarnate at every level.

In between, there's us. And angels, but I don't know enough about them to say anything useful--I have no idea what, if anything, corresponds to them as matter does to us.

We're part of creation, and exemplify the usual ordinary-creation aspects of God: beauty, wisdom, form and order, and so on.

However, we are also capable of knowing these things--a different and more profound manifestation of God's knowledge. We can know, with Him, that He is present and active in our actions.

We are incarnate spirit and matter, and each of these effects the other and to separate the two destroys us. We're shown in scripture that in the resurrection/restoration the body and spirit are remade together. This form of "amphibian" God called good. A body with a ghost, or an ethereal spirit trapped in matter, are things of horror stories--they're the wrong form, not a true incarnation.

We feel that when we work we leave something of ourselves in the work--and certainly some of our time and thought went into what we did, and from a perspective outside time they're still there, embedding part of us--at least our gifts--in the world. As God displays in His creation, in a smaller way we appear in ours.

There's another possible version of incarnation, which I feel even less qualified to explore--the Spirit of God living in us, in some kind of union with us. Perhaps Theosis?