Summary: Jesus teaches His disciples that the flesh profits nothing and only the Spirit gives life. Many don’t believe and stop walking with Him, but Peter confesses “thou art that Christ, the Son of the living God.”
The key word from last week is “union.” To eat His flesh and drink His blood isn’t literal and earthly but rather spiritual (see verse 63). The idea is that we partake of Him and are united to Him as a man is united to his wife or a body is united to its head and therefore we share in His life. He died to sin and death and so, therefore, have we. He is raised and will live forever and our lives are hidden with Him in God (Col. 3:3).
But most of the people following Him had no understanding of what He meant:
Many therefore of his disciples, when they had heard this, said, This is an hard saying; who can hear it?
Jesus had a lot of disciples at this point but it was about to be pared down. His teaching wasn’t palatable enough for them. In fact, they called it a “hard saying.” The word for hard doesn’t mean that it’s just too difficult to understand. It’s also used to describe a hard and uncomfortable chair. It means something that’s harsh, stiff, and unyielding.
Who can hear it? Or, more accurately, “who is able to hear it?” (τίς δύναται αὐτοῦ ἀκούειν). Who has the ability or power to hear what He’s saying without getting upset about it?
This is a common problem even now. So many people already know what they believe and won’t listen to what Jesus teaches. Instead they get offended and refuse to even think it through. In reality they reject Christ when they do this. We must be careful to always be ready to change our doctrines when they don’t line up with Scripture.
61When Jesus knew in himself that his disciples murmured at it, he said unto them, Doth this offend you?
The word for “offend” means to be a scandal or to cause someone to stumble. Christ crucified is a stumbling block to the Jews, after all (I Cor. 1:23). All this talk about coming from heaven and having life within Himself and consuming His flesh and blood has upset their sensibilities. They can’t and they won’t believe it.
62What and if ye shall see the Son of man ascend up where he was before?
They were offended when He told them He came down (incarnation). They were also offended when He said He’d give His flesh for sin (at the cross). If those things offend them, will they be even more offended if they see Him go back up? No amount of evidence is enough for the hardened heart; the heart of stone. Even if a man rises from the dead they make excuses for it and suppress the truth.
63It is the spirit that quickeneth; the flesh profiteth nothing:
They think He’s talking about literally eating His skin. But there would have been no benefit in that any more than there was for their fathers to go on eating miracle bread. The flesh profits nothing. The word means to be of service or to give an advantage. The flesh can help you in no way. Eating His body is of no use, and reaching God through the flesh is just as useless. Those who eat bread still die (Jn. 6:49). Arguing about which mountain was the best for worship is futile (Jn. 4:20-24). “If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things?” (Jn. 3:12). The temple, priests, sacrifices, and all the celebrations, feasts, and rituals were merely earthly and fleshly. They profit nothing except to point to the spiritual which “quickeneth” or “gives life.”