Eating is the unique way, and God is the unique food to man. Here we have to tell people that all the physical food we eat is a shadow. God is the reality of our food. You can use Colossians 2:16-17 to show this.
I like to use these two words—organically and metabolically. To receive God by eating Him is to have God assimilated into our being metabolically. When we receive God into us, His new element replaces what we are, and our old element is discharged. This is a kind of metabolism. Our physical, organic eating and metabolic digesting and assimilating are an illustration of the eating, digesting, and assimilating of Jesus as our spiritual food. This is not just our concept. This is the deep concept in the whole Bible.
When the Lord Jesus came, He said, "I am the bread of life" (John 6:35a), and "he who eats Me, he also shall live because of Me" (v. 57b). The tree of life is seen in Genesis 2 at the beginning of the Bible and in Revelation 2 and 22 at the end of the Bible. This tells us that the whole concept in the Bible is that man has to eat God, to take God in organically, and to assimilate God metabolically that God may become his "fibers," his "tissue," his very being. The food that we eat eventually becomes our being. We become what we eat. We are a composition of the food that we have assimilated. God today is our food in the same principle.
In Revelation 2:7 the Lord Jesus promised the church in Ephesus that to the one who overcomes He would give to eat of the tree of life. The last promise in the entire Bible is a promise of the enjoyment of the tree of life, which is Christ with all the riches of life (Rev. 22:14).
God did not say anything to Adam regarding the tree of life, but God did say something regarding the tree of knowledge. God forbade man to eat the tree of knowledge (Gen. 2:17).
God's first commandment to man was related to his eating. He charged man not to eat of the tree of the knowledge of good and evil.