It was by design.
The first man Adam was by consequence lost.
The second man Adam is by design saved.
Now, all who are in with the second Adam while yet alive are saved as Jesus is.
All those before Jesus are saved at their visitation when Jesus visited them in prison, otherwise known as hell.
The whole point is that God could not create us as gods, meaning separate from Himself, without the consequence of separating Himself from us by our individuality. As separate entities apart from Him.
He knew that an thus, by His design, He re-introduces the tree of life as Jesus.
Jesus then becomes a new creation of which there is no consequence of our separation, thus reconciliation, and in which becomes our vehicle (Tree of life) to live forever.
Two references:
1. Reason for the two Adams :Rom 8:20 For the creature (1st Adam) was made subject to vanity, not willingly, but by reason of him who hath subjected (2nd Adam) the same in hope, Rom 8:21 Because the creature itself also shall be delivered from the bondage of corruption into the glorious liberty of the children of God.
2. Gen 3:22 And the LORD God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever:
If we look at Rom 8:20, we see the design of the first Adam by verse with the red lettering Gen 3:22 ..."Behold, the man is become as one of us"...
Blessings, AJ