Hebrews 4:15-16 [ESV] For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. Let us then with confidence draw near to the throne of grace, that we may receive mercy and find grace to help in time of need.
Christianity at large agrees with the precept that Jesus did not sin, under the theological category of the doctrine of impeccability. The verse above and others attest to this teaching; however, disagreement exists as to whether or not Jesus could have sinned (for Latin lovers: the debate is between posse non pecare (able to not sin) and non posse pecare (not able to sin); fallen humans are non posse non pecare (not able not to sin)). R.C. Sproul, for example, takes the position that “it was possible for him to sin.” The editors of gotquestions.org disagree. On the Sproul side it is claimed that if it were impossible for Jesus to sin then, “the temptation, the tests, and his assuming of the responsibility of the first Adam would have been charades.” The gotquestions.org responds with the assertion that, “If He could have sinned, He would still be able to sin today because He retains the same essence He did while living on earth.”
The doctrine of the hypostatic union states that at the incarnation the Second Person of the Triune Godhead added a human nature to Himself: fully God, fully human “united without mixture, change, division, or separation in one person forever” (Ryrie, Basic Theology, p. 284). So not half God/half man but fully God and fully man but only one person, and that person is one of three persons: Father, Son, and Holy Spirit. “The whole undivided essence of God belongs equally to each of the three persons” (Ryrie, p. 61). These concepts are difficult to define and even more difficult to fathom as would be expected when a finite created being tries to explain an infinite Creator being.
Still, knowing that Jesus is fully God helps make answering the question, “could Jesus have sinned?” easy. No! Though Jesus is fully human and as a human He fully experienced all of the difficulty of living in a fallen world, He remained one person, which includes being God, and God cannot sin. The gotquestions.org folks make the point that if Jesus could have sinned then he still could. Even if he could, he never would, so what does that really matter? The better argument relates to how could it be possible for God to sin? By definition God cannot sin so in order for it to be possible for God to sin would mean that it would be possible for God to stop being God.
Sproul’s argument that the impeccability of Jesus makes the temptation of Christ a charade appears strong but two analogies might help. First, I am a high school teacher. I give tests to my students on a regular basis and I have taught some truly brilliant young people. For some of those brilliant young people, because of who they are and their drive to prepare well and succeed, it would be truly impossible for them to ever fail any of the tests that I give. That does not make the tests any less legitimate and it doesn’t mean they don’t truly feel the stress of the tests that I give.
More to the point is an analogy from the military. One of the chief fuels that keeps the machine of the military going is rumors. When I was in basic training (soon after 9-11) a rumor persisted that we were getting out of basic early to ship out to Afghanistan. That rumor was truly ridiculous for anyone that knows anything about how the military operates. Short of some sort of Red Dawn event occurring basic training is not getting out early! Still, I hated basic training more than anything and the idea of it ending a couple of weeks early was a great motivator.
After my first deployment to Iraq another rumor began that the Army would be replacing the M-16 with a new rifle called the XM-8, and that my unit would be the first to deploy it! I still think it might be that there was some truth to this rumor, certainly more than to the one about skipping out on a few weeks of basic to go fight the Taliban. The XM-8s were never adopted, however, because they failed some key tests. From what I understand one of those tests was that after high use, the barrel of the weapon began melting.
Here in lies the analogy: comparatively the M-16 does not look as cool as the Starship Troopers looking XM-8, but the M-16 performs better when it counts. And it actually endures much more stress than the XM-8 could, yet without failing. We are like the XM-8. We try to look as cool as possible but all too often when a little sin tempts us, we so easily let it entangle us. Quickly and easily giving in to temptation does not mean that we understand its power more, it actually means we understand it less! The longer we endure under temptation the more awareness we become of its power. My brilliant students understand the tested content better. The M16 endures more stress. And Jesus understands temptation fully. Even under extreme conditions He did not break. Having been fully tested in ways that we so often fail, He can truly sympathize with our weaknesses. Not only that but on the cross, God made Him Who knew no sin to be sin for us, “so that in Him we might become the righteousness of God” (2 Cor. 5:21). He experientially fully understands the power of sin’s temptation and the seriousness of the consequence of giving into that temptation. He can truly sympathize with our weaknesses.
The application of Hebrews 4 is that since our Savior sympathizes with our weaknesses, a true human who has been tested in every way as we have, yet more fully and without failure, we have someone we can go to in our own temptations. We give into the temptations too easily too often and too early but we also have God’s Spirit giving believers in the Lord Jesus Christ their own source of impeccability when we rely on Him during temptation. When we confidently approach our Savior and ask for help, we are asking from one who has been there and done that, without sin, and who cares for us. He knows we can’t do it on our own; He calls us to go to Him and receive unmerited favor to enable us to pass the trials and tribulations of life. It is He who fully defeated sin and its effects and can and will give us aid in our own time of need.
First and Second 
