The penal substitution view of atonement takes the metaphor of sin as debt and literalizes it to the extent that one's actions are viewed in terms of accounting rather than relationship. It is not surprising this is popular: in our time, debts are impersonal and most people have them, and it is easier to think of slates being wiped clean and books being balanced than a need for reconciliation. But the latter is the core element if one thinks of God in personal terms. And for God to forgive, all that the Bible suggests that God has to do is forgive.I've been puzzled for awhile why people hold to penal substitution with such emotional ferocity. In their book Recovering the Scandal of the Cross, Joel B. Green and Mark D. Baker explain the attraction of penal substitution by our society's obsession with assigning blame to individuals.
But I think that McGrath is on to something here. It's the same thing that many Jewish people complain about with respect to Christian forgiveness: that our moral system doesn't require us to seek reconciliation with the people who we have hurt, but that we simply pray to God and all our sins are forgiven.
I think that the popular view of Christianity as practiced in the West has its roots in 'quietest' tendencies. Quietism stems from the idea that sinful human beings cannot be reconciled with God unless God makes the first move. It goes on to say that because human beings can do nothing to be reconciled with God, that any attempt by human beings to 'do good works' is a rejection of God's grace. So any attempt to grow in holiness is often condemned as not believing in salvation by faith alone.
This whole system turns Christianity into a 'God and me' religion. God saves me by grace - however I think that happens - and then I don't actually have to change anything in my life. If I wrong someone, all I have to do is pray to God for forgiveness; I don't need to attempt to communicate or reconcile with the person whom I have wronged. 'Reconciliation' thus remains a 'spiritual' thing between me and God and it imposes no difficult practical demands on my life.