What is the origin of "cruciform theodicy"? The philosophical Problem of evil concerns the existence of evil, specifically how it can be that evil exists in the world even though God is said to be both omnipotent (all powerful) and omnibenevolent (all good). If God was omnibenevolent but not omnipotent, then he may not be able to dispose of evil, or if he was omnipotent but not omnibenevolent he may not want to. But Christianity teaches that he is both, leading to the tricky conclusion that God should be both able to eliminate evil and desire to do so, and yet he has not. This is the Problem of evil, and there have been many theodicies (defences of God) proposed over the ages.

The Wikipedia page on the problem of evil cites Dietrich Bonhoeffer as the originator of "cruciform theodicy" when he wrote this in 1944: 


  Only the suffering God can help.


But were there previous Christian writers who claimed that Christ's suffering on the Cross contains the answer to the problem of evil? What is the origin of cruciform theodicy?

Note: this question is not asking about the problem sin and evil as they pertain to us, of how we can be forgiven, saved, and restored to perfection. If your answer does not directly discuss the attributes of God it may not be a valid answer.
Here is an early writing which may have been part of what influenced Bonhoeffer in the direction of cruciform theodicy.  It comes as part of a letter from Ambrose of Milan to the Christian congregation at Vercellae in 396 AD.  In staunch opposition to Epicurean Philosophy (from whence comes the Problem of Evil in it's original formulation) Ambrose points out that pleasure cannot reinstate us to Paradise because pleasure alone has caused us to lose it.


  But Holy Scripture refutes this, for it teaches us that pleasure was suggested to Adam and Eve by the craft and enticements of the serpent. Since, indeed, the serpent itself is pleasure, and therefore the passions of pleasure are various and slippery, and as it were infected with the poison of corruptions, it is certain then that Adam, being deceived by the desire of pleasure, fell away from the commandment of God and from the enjoyment of grace. How then can pleasure recall us to paradise, seeing that it alone deprived us of it?


If pleasure cannot avail us of it, perhaps the unspoken opposite of suffering is implied as the cure.