Was it possible for Jesus to sin? The Bible is quite clear that Jesus did not sin. Paul says that Jesus "knew no sin" (2 Corinthians 5:21). John confirms that "in Him there is no sin" (1 John 3:5). None of His enemies could convict Him of sin (John 8:46).
But could He have sinned? Hebrews 4:15 tells us that "we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin." If it wasn't possible for Jesus to sin, then was His temptation genuine?
It's more fitting to say that while He could have sinned, it was certain that He would not. He faced genuine struggles and temptations, but refused to give in to the temptation to sin.
When He was tempted of the devil for 40 days and nights (Luke 4:1-2), was this real temptation or merely a pointless exercise? One could hardly say that His "prayers and supplications, with loud cries and tears, to the one who was able to save him from death" were not a result of experiencing strong temptation.
Such a time came when He prayed under such duress immediately before His arrest that, "being in agony, He prayed more earnestly. Then His sweat became like great drops of blood falling down to the ground" (Luke 22:44). Jesus then urged His disciples to "rise and pray, lest you enter into temptation" (Luke 22:46).
For Jesus to fully know how human beings have to deal with sin, "...he had to become like his brothers and sisters in every respect, so that he might be a merciful and faithful high priest in the service of God, to make a sacrifice of atonement for the sins of the people. Because he himself was tested by what he suffered, he is able to help those who are being tested" (Hebrews 2:17-18, NRSV).
How could He be our example if He wasn't human and therefore wasn't tempted exactly as we are? This is why He had to be tempted in every way as we are. Yet He went beyond. If a person yields to temptation, he has not felt its full power, but has given in while he has yet more to resist. Only the one who successfully prevails against a particular temptation and remains sinless knows the full extent of that temptation.