In John 6:35 Jesus said, "I am the bread of life"- he is the source of life. But the life Jesus is talking about isn't physical life, but he is teaching that he is the source of living - of quality in life. He is teaching that just as we need food to give us the nutrients to thrive physically, in the same way a relationship with Jesus is the source of meaning and gladness that makes like not only survivable, but meaningful and enjoyable.