I don't think I am mistaken. Luther puts it very strongly: 'Paul therefore doth very well allege this general sentence out of Moses, as concerning Christ: "Cursed is everyone that hangeth on a tree." But Christ hath hanged on a tree, therefore Christ was accursed of God' [Commentary on Galatians 3:13. The full commentary on this verse is very extensive and well worth reading]
I am a Christian first, but then R.B..
People never believe they are mistakin when they are mistaking error for truth. ;)
The difference is neauenced. Luther based the atonement on merit rather than retributive punishment.
I am sure you will he able to see the difference between Penal Substitution Theory and Luther in this sermon excerpt:
"But now, if God’s wrath is to be taken away from me and I am to obtain grace and forgiveness, some one must merit this; for God cannot be a friend of sin nor gracious to it, nor can he remit the punishment and wrath, unless payment and satisfaction be made.
Now, no one, not even an angel of heaven, could make restitution for the infinite and irreparable injury and appease the eternal wrath of God which we had merited by our sins; except that eternal person, the Son of God himself, and he could do it only by taking our place, assuming our sins, and answering for them as though he himself were guilty of them.
This our dear Lord and only Saviour and Mediator before God, Jesus Christ, did for us by his blood and death, in which he became a sacrifice for us; and with his purity, innocence, and righteousness, which was divine and eternal, he outweighed all sin and wrath he was compelled to bear on our account; yea, he entirely engulfed and swallowed it up, and his merit is so great that God is now satisfied and says, “If he wills thereby to save, then there will be a salvation." (
Sermons of Martin Luther, vol. 2, p. 344)
Now, I do not believe Luther is necessary correct (I hold the classic view) BUT Luther's view - while similar- obviously is not Penal Substitution Theory.