Well, according to Genesis, eating of the Tree of Life grants immortality. It was to prevent Man from acquiring it that Adam was driven from the garden, and more specifically, he was stopped from eating the fruit of the tree. If Jesus is going to lead his followers to the tree then God must have changed his mind.Why will Jesus let us eat out of the tree of Life in the new ?
" 'The man has become like one of us, knowing good and evil; what if he now reaches out his hand and takes fruit from the tree of life also, eats it and lives for ever?' So the Lord God drove him out of the garden of Eden...." (Genesis 3:22-24)
What has changed? God previously guarded against Man acquiring immortality. Adam was driven from paradise to prevent it happening. Why does he relent now; or rather, why did he promise 2000 years ago to offer at last what he has always refused to grant? Note, it is still, after 2000 years, an unkept promise.
Oh, and receiving immortality in death is not the same as receiving immortality in life.