Jesus crucified. God crucified. I think the emphasis here is because of the assumption of Christianity on the part of Paul’s audience. To emphasize the resurrection would be to try to make a point of His divinity, or at least His favor with God. To emphasize His crucifixion, I think, is to highlight the very first days of the covenant made with Abraham.

And he said to him, “I am the LORD who brought you from Ur of the Chalde’ans, to give you this land to possess.” But he said, “O Lord GOD, how am I to know that I shall possess it?” He said to him, “Bring me a heifer three years old, a she-goat three years old, a ram three years old, a turtledove, and a young pigeon.” And he brought him all these, cut them in two, and laid each half over against the other; but he did not cut the birds in two. When the sun had gone down and it was dark, behold, a smoking fire pot and a flaming torch passed between these pieces. — Genesis 15:7-10, 17

In these days, a covenant was formed in this manner between two peoples, and whoever would violate the covenant would bring about the same fate upon himself as that of the animals cut in two.

And the men who transgressed my covenant and did not keep the terms of the covenant which they made before me, I will make like the calf which they cut in two and passed between its parts — Jeremiah 34:18

So man, as the party who violated the covenant, needed to die because the covenant was broken. In order to fulfill the covenant so that a new covenant could be created, one of the parties needed to die — to fulfill the covenant curse. While we were the ones who deserved death, God died in our stead.
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It also points to how we are to live in Christ now. We hope to God’s mercy when we die, so that we may live with Him in His glory forever. But for now, we look to His Son. In particular, we look to His Son on the cross, which is the best example of self-giving love that the world has ever seen. Think not to your own comfort, but give everything for the good of others. Be ridiculed and mocked, so that they can come to know Truth. Allow yourself to be beaten and scourged, so that they can have access to a Love which heals all hurts. Wear their crown of thorns, so that they can have their own minds be filled with Wisdom. Carry for them the dead weight of their troubles and sins. Have your hands and feet be bound to a tree with spikes, so that they can experience freedom. Experience a moment of feeling abandoned by the Father, so that they may know they are never alone. Give up your Spirit, so that they may receive it.

He did not just allow blood to flow from His wounds so as to heal ours, but squeezed out every drop.

This is the kind of life we are called to lead. If God sees to the birds of the air and the lilies in the field, certainly He can take care of our needs; so we have no reason to dwell on our needs, but can look solely to our neighbor in love and ask ourselves, “How can I squeeze out some of my blood on his behalf, to make his lot in life a little easier?” Not a passive bleeding, as in handing over the spare five you happen to have in your wallet, or giving away clothes you don’t wear any more — although these are not bad things to do. But what can you do that will really be a sacrifice? What’s going to make you stop and think about it, and then deliberately decide that the person is far greater and far more worthy than any object, amount of wealth, amount of time, amount of effort that you could possibly relinquish?

And when you have done something really worthy of being called Love, seek out another situation, another person to Love, another instance where you can pour out the blood of your life for someone else.

For your blood is not your own; it is His. Your life is His life in you.

And He wants it to fall upon all His people.