What does Paul mean? Did Israel eat spiritual food when they ate the manna? When the Jews said to Christ, ‘What sign shewest thou then, that we may see, and believe thee? what dost thou work? Our fathers did eat manna in the desert; as it is written, He gave them bread from heaven to eat’, the Lord answered them, ‘Verily, verily, I say unto you, Moses gave you not that bread from heaven; but my Father giveth you the true bread from heaven. For the bread of God is he which cometh down from heaven, and giveth life unto the world’ (John 6:30-33).
Just imagine you were eating and drinking of God's direct provision every day. What would you say to yourself, if there was some place to which believers only had access, and we were divinely provided for? You would say, ‘Well that would be a magnificent stream of assurance; that would hold me up. I would never doubt again, if I had a demonstration like that by the miraculous power of God every day.’ You would think so, wouldn't you? But that is what they had, and yet they fell. So the apostle Paul is making powerful points to the Corinthians, in puncturing their pride and showing just how much the fathers, and yet they fell. This is a going to be the great point.