Enlightenment:
In verses 22 through 31 we find the seekers after the perishing food. They were seeking satisfaction. Regardless of the kind of food people are seeking, they all are seeking satisfaction. They were also seeking for signs and miracles. The concept of fallen man toward God is always that he must do something for God and work for God. This is the principle of the tree of the knowledge of good and evil in Genesis 2. The Lord’s concept concerning man toward God is that he believe in Him, that is, receive Him as the life and life supply. This is the principle of the tree of life in Genesis 2. The answer to the seeking after the perishing food is to receive the Lord by believing into Him (6:29).
The human, religious concept is what the Jews asked in verse 28: “What shall we do that we may work the works of God?” Throughout the Scriptures, it is only in this chapter that the religious Jews asked such a question. Religious teaching always exhorts us to do and do. Man’s concept is doing; God’s thought is believing.
The work that God desired and predestinated for us to do is to believe into His Son. The preposition “in” in verse 29 (“on” in KJV) should be translated as “into” according to the Greek text. The Lord Jesus did not tell us to believe Him, but to believe into Him. John 6 shows two ways of believing—to believe Him and to believe into Him. After the Lord answered their question, the Jews retorted in verse 30, saying, “What sign will you do that we may see and believe you? What work will you do?” They said, “Believe you,” but that was not what the Lord said. The Lord told them to “believe into Him.” The preposition is exactly the same as that used in Romans 6:3 for “baptized into Christ.” As we have seen, to believe Him means to believe that He is true and that everything about Him is right. But to believe into Him means to receive Him and to be united and mingled with Him as one. When you believe into Him, there is a union and a oneness between you and Christ. In other words, you have come into Him and have received Him into you. According to the divine thought, there is nothing for us to do but to believe into Christ and receive Him into us day by day.