Posted another comment over at Tony Jones' post A Straw Man on the Cross?. Good debate and if this stuff interests you, take a look and jump in.
I had posted that my primary problem with the penal substitutionary atonement is this:
God's immutable nature creates immutable laws that constrain God's action and we are ultimately beholden to an idea of the substantial nature of God via analogia to human attributes which then forces the issue of the relationship of law and sin. It is this structure which ultimately governs PSA that I think is not necessary and so, PSA is not necessary.
Another commenter asked:
The question is a strange one since it is on face value impossible to affirm. It is like asking me if my voice is ever dependent from my body (let's assume without various recording and digital manipulations we can build today 
).
Ultimately, the question is dependent on how one asserts the nature of God to be. I take a compatibilist view where the nature and the will are essentially co-determinative. They may be logically distinct, but form and function & nature and will are in actuality of the same construct. In other words the answer is no, but equally true is to say that God's nature is never free from God's will. Apart from this construct, the next part of the line of question is if God's nature is X, then we can and ought to assume the will Y to operate under certain conditions. This works if you are look at it in a linear cause/effect manner. A compatibilist view cannot conform to such a structure – especially if applied to the nature and will of God. After all a perfect circle has no beginning and no end.
Another analogy is to say that the being and act of God is not unlike complementarity in physics. There we can look at the same object, but the objective qualities of that object take on different structures depending on our view of it. So if you look at light one way it is a particle. If you look at it another way, it is a wave. It is not that is appears to be a particle or wave, it actually is either a particle or wave depending on how you measure it. In similar fashion, God's nature and God's will are each co-determinative depending on how you limit your field of view, in this case, those Scriptural narratives you take to be constructive of God's nature and/or will that are logically prior.
Related posts:
