We are now in that area of theology called theodicy -- attempting to justify the ways of God toward men. Petrel's comments remind me of how the poet MacLeish frames the issue, putting into the mouth of his character, J.B. (a modernization of Job), the couplet, "If God is good, He is not God; if God is God, He is not good."
But that is all from our human perspective. It is not so much that God sends us to hell, some location of eternal torment, as it is that we send ourselves to isolation from Him. We put ourselves into "hell" -- the anguish of broken fellowship. And so grace means that God Himself accepts our brokenness, suffers it Himself on the cross, and reaches out to draw us to Himself. If we choose not to accept the invitation, we will continue to suffer -- but that's not about the arbitrariness of God. That's about our self-destructive sin.
By the way, I don't think there is or ever will be a satisfactory answer to the intellectual puzzle that theodicy poses. But for me there is a satisfying spiritual answer -- "Look, Father, look, on His anointed head, and only look on us as found in Him. For lo between our sins and their reward we set the passion of Thy son, our Lord."