https://faith.edu/faith-news/the-impeccability-of-christ/
Answers to Objections
1. “If Christ could not have sinned, His temptation was not real.” M.R. DeHaan says, “There is but little glory in not sinning when it is IMPOSSIBLE to sin” (The Temptation of Jesus, p. 13). Again DeHaan says (p. 19), “Therein lies the glory of His victory—not that He could not sin—but that HE WOULD NOT SIN. Otherwise there could have been no temptation.”
The answer to this objection is that there can indeed be a genuine temptation without the possibility of Christ’s yielding to it. This is because temptability does not imply that the one being tempted must be able to yield to the temptation Walvoord (Jesus Christ Our Lord, p. 147) states, “While the temptation may be real, there may be infinite power to resist that temptation and if this power is infinite, the person is impeccable.”
Related to this objection is the idea that true freedom involves the possibility of choosing to sin. Yet we know that God has free will (Ephesians 1:11) and it is impossible for Him to lie (Titus 1:2). Francis Pieper (Christian Dogmatics, II, p. 76) remarks, “The assertion that ‘freedom’ must always involve the possibility of sinning operates with a false conception of freedom. The saints in heaven cannot sin, and still they are not unfree, but enjoy a state of perfect freedom.”
2. “If Christ could not have sinned, then He cannot be our example as Hebrews 4:15 says He is.” This is DeHaan’s argument (The Temptation of Jesus, p. 8).
The answer to this objection is that the parallel between our blessed Lord and ourselves is not that because He conquered temptation we can also. How could such a parallel exist? He had no sin nature. We do. He never sinned. We do. Our sin nature offers the tempter an inward point of temptation. This was missing in Jesus. Hebrews 4:15 does not say that Jesus was tempted so that He could be our example, but so that He could sympathize with us. He was human. He got tired. He was hungry. In this sense His temptations were real and in this sense He can understand when we, too, become weary. But this is vastly different from saying Jesus Christ could have sinned. Berkhouwer (The Person of Christ, p. 254,255) clearly presents this truth.