What's at Stake if God Suffers in His Divinity?

One of the earliest heresies surrounding the question of divine suffering is known as patropacianism. The idea was that, you know, the, the Father suffers on the cross too. If God were passable in his divinity, theologians say part of some larger ongoing thing, he would be part of the world. We would have to conflate the existence of the world and the existence of God, and end up with a kind of pantheism or something.