Even Calvinists need to be humble. I preached all the way through John chapter 6 without using the word Calvinism once, though I most assuredly taught the truths from John 6 that Calvinism seeks to summarize. The Father chose a group of people to give to His Son. The Son gave His life, His flesh, for that group. The Spirit brings that group to life, giving them the desire to come to the Son. Each person in the group is guaranteed to be raised on the last day.
Not a one of them deserved it. They were hungry and Christ fed them. They could only behold Christ through unbelief until the Spirit opened their eyes. They were prone to walk away, and all of them would have except that Christ keeps them.
Peter’s affirmation of truth (in verses 68 and 69) was met by Jesus with another affirmation: Peter (and the staying disciples) believed because they were chosen (verse 70). There was no place for presumption, no place for uppityness, no reason to pat themselves on the back for theology well spoken. But for the grace of God they would have walked away with “many of His disciples” (verse 66).
Our time at the Lord’s table is similarly humbling. We affirm our belief that His sacrifice for sins is our only hope. We confess our personal trust in Christ when we eat and drink. We share a meal of peace with God and with God’s people. And the fact that we can do so says more about God than about us. But for the grace of God, we would walk away from the Table, not towards it.
We have every reason to be humbly thankful. We have every reason to boast in Christ. We have every reason to come to Him. He chose us for Himself.