In Greek the word for tree here, as in 1 Pet. 2:24, means wood; it is not the word usually used for tree. In the Bible the tree of life always signifies Christ as the embodiment of all the riches of God (Col. 2:9) for our food (Gen. 2:9; 3:22, 24; Rev. 22:2, 14, 19). Here it signifies the crucified (implied in the tree as a piece of wood — 1 Pet. 2:24) and resurrected (implied in the life of God — John 11:25) Christ, who today is in the church, the consummation of which will be the New Jerusalem, in which the crucified and resurrected Christ will be the tree of life for the nourishment of all God's redeemed people for eternity (Rev. 22:2, 14).
God's original intention was that man should eat of the tree of life (Gen. 2:9, 16). Because of the fall, the way to the tree of life was closed to man (Gen. 3:22-24). Through the redemption of Christ, the way by which man could touch the tree of life, which is God Himself in Christ as life to man, was opened again (Heb. 10:19-20). But in the church's degradation, religion crept in with its knowledge to distract the believers in Christ from eating Him as the tree of life. Hence, the Lord promised to grant the overcomers to eat of Himself as the tree of life in the Paradise of God, as a reward. This is an incentive for them to leave religion with its knowledge and return to the enjoyment of Himself. This promise of the Lord restores the church to God's original intention according to His economy. What the Lord wants the overcomers to do is what the whole church should do in God's economy. Because of the church's degradation, the Lord came to call the overcomers to replace the church in the accomplishing of God's economy.
The eating of the tree of life not only was God's original intention concerning man but also will be the eternal issue of God's redemption. All God's redeemed people will enjoy the tree of life, which is Christ with all the divine riches as the redeemed's eternal portion for eternity (Rev. 22:2, 14, 19). Because of religion's distraction and the church's degradation, the Lord in His wisdom made the enjoyment of Himself in the coming kingdom a reward in order to encourage His believers to overcome religion's distracting knowledge in teachings and return to the enjoyment of Himself as the life supply in the church life today for the accomplishing of God's economy.
Eating the tree of life, that is, enjoying Christ as our life supply, should be the primary matter in the church life. The content of the church life depends on the enjoyment of Christ. The more we enjoy Him, the richer the content will be. But to enjoy Christ requires us to love Him with the first love. If we leave our first love toward the Lord, we will miss the enjoyment of Christ and lose the testimony of Jesus; consequently, the lampstand will be removed from us. These three things — loving the Lord, enjoying the Lord, and being the testimony of the Lord — go together.