With my own eyes I’ve seen your salvation; it’s now out in the open for everyone to see: A God-revealing light to the non-Jewish nations, and of glory for your people Israel. (Luke 2:32 MSG)
God made no attempt to enter into this world "under cover". He sent his Son, not as an "under cover God", but as God with a bod. He took on human form, coming as light to a dark world. Light just cannot be hidden - it has a way of finding a way out of the darkness, but best of all - it has a way of helping each of us find our way out of darkness.
Jesus could have come in any form, but why take on human form? It is pretty simple actually - we needed to "relate" to him. We might have heard of his power, seen his miracles, and even studied his existence, but to see him embody the very "form" of mankind revealed something of his love that actually allowed us to connect with him. That connection was only possible because of his ultimate sacrifice on the cross, though. While his birth, taking on human form, was very important and a little bit impressive, it wasn't nearly as important or impressive as his death, burial and resurrection!
Restored relationship required more than being able to "relate" to God with a bod. It required the blood sacrifice we never could offer ourselves - the blood sacrifice of the truly "perfect Lamb". While not growing up during the times of sacrificial offerings on the altar of fire, I can tell you the selection of the sacrifice was very important, yet still very imperfect. As close to perfection as that sacrifice came, with as little evidence of blemish as it had, that animal sacrifice was still not totally without blemish! It had no way of fulfilling the ultimate need of humankind. Only Christ could do that.
And so he did .... in being born, he lived among us. In living among us, he showed us aspects of his love and goodness we could not really understand apart from that example he left with us. In facing opposition greater than most of us will ever endure in a lifetime, he revealed something of his strength and character that only a God with a bod could show us and help us to hold onto in our own times of personal conflict. In coming, he prepared to leave again - not in a kind and humane manner - but in the ultimately awful death of the cross. In leaving again, he prepared the way for his return.
None of us really could relate to God in the way we do today apart from that coming and ultimately in that leaving. It is this connection he made that helps us to "relate" to the righteousness of God because that righteousness has been made ours in his life lived on our behalf, and his death in perfect human form - a sacrifice too great for any of us to ever accomplish. Light came, we tried to snuff it out, but it shines on and on and on. Just sayin!