...and should be converted... converted to what? The complaint is that Christianity is something new, that Judaism is being added to, the Law is being removed/diminished. The Law is not diminished it is being fulfilled in one person. It is not being added to, it is being completed in the manner it itself has long prescribed. It is not something new if it's leader is someone anticipated ever since kjv@Genesis:3:15.
A great many things are given and allowed in the garden. One simple thing is not. It is the one thing that often occupies our mind. People are to some extent defined by what they can't have, by what is forbidden just as they are defined by the fear of death. Not only is there what is forbidden, there is what is threatened, and there is someone readily willing to deceive.
The deception is a subtle twist of words over the meaning/extent of death. If the serpent had said that she'd die spiritually first, be exiled from the garden, live her and her generations in toil and turmoil, suffer famine and war and horrid transgressions from one another, and die a slow degenerating sometimes cancerous death, the deception would not have been as inviting. What is at question here is whether God would stand behind what He said and follow through; if so why? The why gets us into areas far beyond the thoughts of man.