The bible says that if sinners ate the tree of life they could live forever though they sinned. However, God blocked the way to the tree of life so that sinners couldn't eat the tree of life.

Ge 3:22~24 And the Lord said, "The man has now becone like one of us, knowing good and evil. He must not be allowed to reach out his hand and take also from the tree of life and eat, and live forever." So the Lord God banished him from the Garden of Eden to work the ground from which he had been taken. After he drove the man out, he placed on the east side of the Garden of Eden cherubim and a flaming sword flashing back and forth to guard the way to the tree of life.

Then, what is the reality of the tree of life in Eden? Jesus taught us that the tree of life is a parable. (Mt 13:34~35)

Jn 6:53~54 Jesus said to them, "I tell youbthe truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day."

The bible clearly tells us that whoever eats Jesus' flesh and drinks Jesus' blood has eternal life. And to have eternal life we should eat the tree of life in Eden. Let's think it over. The flesh and blood of Jesus gives the eternal life and also, the tree of life gives the eternal life. What does it mean? It means that Jesus' flesh and blood is the reality of the tree of life.

Then, how can we ear His flesh and drink His blood? It is the Passover of the new covenant that Jesus established.

Mt 26:26~28 While they were eating, Jesus took bread, gave thanks and broke it, and gave it to his disciples, saying "Take and eat;this is my body." Then he took the cup, gave thanks and offered it to them, saying, "Drink from it, all of you. This is my blood of the covenant, which is poured out fro many for the forgiveness of sins.

Comparing Jn 6 and Mt 26, the Passover is the way to eat Jesus' flesh and drink His blood, that is, the tree of life.
All men are sinners who committed sins deserving death sentence in heaven. The only way to receive eternal life and be free from death is to keep the Passover.