I don't know why some conversations are so memorable while most are quickly forgotten. One that is memorable for me is a short exchange I had while in Seminary at Asbury. I don't remember who the conversation was with but it occurred after some professor in some class, theology or church history, briefly explained a position on the atonement sometimes called "Ransom Theory" where a "ransom" was paid to Satan in the atoning death of Christ. This view was not being supported by the professor but simply presented as a view that had been held by some in the history of the church. I remember saying to a classmate that I believed in a ransom but that the ransom had been paid to God, not Satan. My classmate wasn't too impressed with my point of view and said something like, "well that's not very palatable." I was interested to read something by John Piper though in his devotional book, The Passion of Jesus Christ. In this book Piper writes of "fifty reasons why He came to die." In the chapter I read last night Piper wrote:
There is no thought in the Bible that Satan had to be paid off to let sinners be saved. What happened to Satan when Christ died was not payment but defeat......If we ask who received the ransom, the biblical answer would surely be God. The Bible says that Christ "gave himself up for us, [an] . . . offering . . . to God" (Ephesians 5:2). Christ "offered himself without blemish to God" (Hebrews 9:14). The whole need for a substitute to die on our behalf is because we have sinned against God and fallen short of the glory of God (Romans 3:23). And because of our sin, "the whole world [is] held accountable to God" (Romans 3:19). So when Christ gives himself as a ransom for us, the Bible says that we are freed from the condemnation of God. "There is therefore now no condemnation for those who are in Christ Jesus" (Romans 8:1). The ultimate captivity from which we need release is the final "judgment of God" (Romans 2:2; Revelation 14:7).
So basically Piper articulated the view that I tried to argue for some years ago when I was much more unsure about what I believed. I can say now that I think the view supported here by Piper, that is, Penal Substitution, is central the gospel and necessary for faithfulness to Scripture, Old Testament and New Testament, in understanding what took place on the cross.