After being asked by some Lutherans (who we thought would know) where the quote on John 6 came from, the ALs met and unanimously agreed to post the source of the quote.
Apology of the Augsburg Confession, Article XXIV, para. 75
To paraphrase LeVar Burton, don't take our word for it. Look it up yourself. And read the context. Actually, read the whole of Article XXIV. While you're at it, start reading the whole book. We know it's thick. Don't panic. The new one from CPH has a handy reading guide. You'll have it read in a year. Then you can stump your pastor. Enjoy.