Our fathers ate the manna in the wilderness. As it is written, 'He gave them bread out of heaven{Greek and Hebrew use the same word for "heaven", "the heavens", "the sky", and "the air".} to eat.'"
The true bread that Jesus came to give was his flesh and blood offered in sacrifice. Unless people eat and drink this ‘food’ they cannot be saved. That is, unless they accept Jesus’ sacrifice for themselves in faith, they cannot have eternal life, either now or in the future (John 5:52-59).