Two Sundays back, while out of town, I had the pleasure of preaching from John 6. As I was preparing to preach from the text of John 6, it struck me that Jesus in revealing himself as the Bread of Life was also revealing his function as such:
“And this is the will of him who sent me, that I should lose nothing of all that he has given me, but raise it up on the last day. For this is the will of my Father, that everyone who looks on the Son and believes in him should have eternal life, and I will raise him up on the last day.” (vv. 39-40 ESV, emphasis added).
Jesus’ promise of raising up those whom the Father has given to him, and who will therefore come to him, is repeated several times throughout this discourse (vv. 44, 54). Precisely because as the Bread of Life, it is Jesus’ function to sustain those who look to him for salvation–those who continue to feed on him.
The doctrine of the eternal security of the believer says that the person who is truly saved will never truly lose their salvation. Some term it once-saved-always-saved or the perseverance of the saints.
But some of Jesus’ disciples quit following him because they were offended at his “hard saying” (v. 60). However, these were not genuine followers of Jesus. Jesus himself knew this (v. 64).
As for Judas Iscariot, Jesus calls him a devil (v. 70). Judas did not truly belong. I came to this conclusion not merely on what Jesus says here, but also by what he says in John 17:12. Why Judas was numbered among the Twelve but was doomed for destruction, remains at best a mystery to me. But enough is revealed in Scripture for the reader to affirm the doctrine of the eternal security of the believer.