Is penal substitution only a recent "theory" of the atonement? How do we understand other images or interpretations of the atonement?
How essential is the trinity in understanding the atonement? Why does God need to kill anyone in order to forgive? Does true forgiveness require a payment or sacrifice?
How was Jesus forsaken on the cross?
If you don't believe any essential Christian doctrines, why would you call yourself a Christian?