One effect of Adam and Eve eating fruit from the tree of the knowledge of good and evil was that they were deceived into believing that they could know good from evil, and right from wrong, apart from God revealing these things to them. Just as all people were cursed with death by being children of Adam, we all have received this curse of trying to be independent of God for the knowledge of good and evil.
When God told Adam and Eve not to eat of the one tree, which He called the Tree of the Knowledge of Good and Evil, He told them that they could eat of the rest of the trees, including the Tree of Life. He could have named these two trees the Tree of Death and the Tree of Life. I believe that He didn’t refer to them this plainly so that He could emphasize the fact that both the knowledge of good and the knowledge of evil that come from the Tree of Death are deadly.
Paul taught the congregations in Rome that the law God gave Moses to make a covenant with Israel and cause them to become a nation was given so that humans could be convicted of sin. Please read Romans chapters 5 through 8 (at least 5:20 and 7:7-10).
The law was not given to gentiles, and the law was not given to Israel so that they would become righteous by learning right from wrong through it. God has given us His Spirit to teach us His righteousness ways.