Some introductory notes on penal substitution, largely derived from the relevant sections of Horton's The Christian Faith. Below might seem like basic Sunday School proof-texts. In large part it is. I am well aware of the nuanced discussions of this issue. My point is that if you posit a God who isn't wrathful and a Savior who can't take the guilt of another to himself, then a lot of the Bible just won't make sense. At least the guys at OB admit they can't deal with "wrath" or Isaiah 53.
Rooted in the Covenant
Our understanding of penal substitution must first be rooted in the covenant. Jesus is the Melchizidekian High Priest, and a change in priesthood requires a change in covenant (Hebr. 5:6, 10). This presupposes that we are already talking about the covenant. If any discussion of the atonement doesn't have the covenant in mind, it's already deficient.
It is Bloody
Instead of shying away from criticisms that the Reformed model makes God look mean, let's throw the criticisms back at them. Quick question (and for the moment we are assuming God's ordained power): Can God forgive me without bloodshed? See here for the answer. Furthermore, in the Old Covenant our sins were transferred to the animal victim (Lev. 1:4).
It Makes Peace
Christ's death secured our peace with God. True, God did love us while we were yet sinners, but he could not fellowship with us. If we were already in a relation-of-peace, then why did Christ need to die? Why would Paul bother to write Romans 5:1?
It is a United Action
This is to rebut the charge that an angry Father killed his Son. People who parrot this charge are a) either ignorant of basic Reformed theology or b) willfully portraying something else. The first is to be pitied. The second is to be called to repentance.
- The Father gave his only Son out of divine love (John 3:16).
- The Spirit vindicated the Son's death by raising him from the dead (Romans 4:25).
- Jesus himself is a willing sacrifice (John 10:11).
Yet, it was a Judicial Punishment
The Greek words anti and huper are substitutionary. There is no getting around it. Pace Anselm, Jesus pays the price to God's justice (not his feudal dignity) and is able to buy back his people (1 Cor. 6:20).
And God's Simplicity
God's simplicity prevents us from exalting anyone attribute (e.g., "love") over another attribute. God's wrath is not arbitrary or capricious, but is a judicious response to the violation of his law and covenant. He is righteous and his law requires that the wages of sin is death (Romans 6:23).
Propitiation or Expiation?
Since the mid 19th century liberal theologians, embarrassed by passages that say God is wrathful, said hilasmos means expiation (clearing me from guilt or bringing me to a state of rectitude), not propitiation (placating a wrathful God). Linguistically, the word can probably go either way (and in previous times the distinction between expiation and propitiation was not always sharply defined). Truthfully, I think the word is best glossed as "mercy-firmament," but that's for another day.
If all it means is hilasmos then it is rather anti-climactic in Romans. In Romans 1:18 Paul says the "wrath" of God is revealed from heaven against all unrighteousness. In chapter 1 he lists how Pagans are guilty before God. In chapter 2 he lists how Jews are guilty. He draws it together in chapter 3. With this background of "wrath" and guilt, which is the more probable translation, expiation or propitiation?