How important is death?
So important that God had to become mortal and die - in order that we could be saved (to everlasting life).
This is the mystery of Christ's incarnation and atonement. Why did God need to become a Man and actually die in order to make salvation possible?
This is, I think, what seems so impossible and ridiculous to other (non-Christian) monotheists - the idea that Almighty God the creator would have to become a Man and die in order to save Mankind!
This is 'incredible', not obvious, not common sense - it is more a doctrine of the weakness of God, the limitations of God, than of His power - yet it is close to the essence of Christianity: pretty much what all Christians must believe to be Christian.
Christianity - it's literally incredible.