Christians cling to Hebrews 4:15. The thought that Jesus endured the temptation that we endure is a source of comfort for grieving, exhausted, and abandoned people. It seems this comfort is what was intended by the author of Hebrews as he then presses us the next verse to come to the throne of grace in prayer with confidence and grab hold of the mercy promise. However, there hangs in verse 15 a clause placed as if it were an asterisked point. That, though Jesus was tempted as we are, he was tempted "without sin" (χωρὶς ἁμαρτίας). What does this mean?
Some have taken this to mean that Jesus himself was without sin. Though, that doesn't seem to be what is taking place here grammatically. The phrase "without sin" seems to modify not the person of Jesus (though it is right to say that Jesus is indeed without sin) but rather it seems to modify the nature of the temptation. This would then mean that the temptation that is being discussed is that which is not sin in and of itself. We see a similar distinction made elsewhere in James 1:13 where it says that "God cannot be tempted by evil". This naturally leads to the question, how can we understand this distinction that seems to be taking place between a non-sin temptation and a sin temptation?
Simply put, we can understand sin to be of two sorts: 1) that which approaches the person from outside of themselves and 2) that which arises from within the person themself. Bavinck refers to these as temptations from without and temptations from within. We can easily think of examples to fit this first category. Particularly, we can imagine very inconsequential temptations such as a piece of chocolate cake while you're on a diet. However, this second category of temptation is quite different and it is this sort that is excluded by the author of Hebrews asterisk point "yet without sin". That is, this second category applies only to people who have an inner disposition toward sin. Jesus not encountering this category of temptation is important because the only way for one to encounter temptations of this sort (such as sexual temptation) is if they themselves have a fallen nature whereby they are inclined toward sin. Jesus (though T.F. Torrance would disagree) did not have a fallen nature. Geerhardus Vos makes a similar connection in his Reformed Dogmatics. He writes,
Will or intellect or emotion in the human nature could not have sinned unless the underlying person had fallen from a state of moral rectitude. There can naturally be no thought of the latter for the Mediator, considering the deity of His person.
For some this cheapens the temptation dynamic at play in Hebrews 4. However, this actually bolsters it! Jesus was tempted in every way possible without compromising his holiness. If he were to be tempted just like me in temptations that arise from within my sinful nature, he would be just as lost as I am (WCF 6.4). This is good news for us that our God, even in his incarnation, is not quite like us!