People who want to redivide Jerusalem - to get back to the anomalous situation that occurred for a mere nineteen years - rarely give a real reason why such a move would not entail, well, a situation very close to how life in Jerusalem was during those years.
Here is just one reporter's description of Jerusalem from January 1962:
Today, Jerusalem is the opposite of what is described here - it is a beautiful, thriving, and growing city. Anyone who wants to divide Jerusalem wants to kill it.
And don't try to argue that "this time will be different." No peace plan can impose security for Jews on the Arab side, and any forays by Jews to their holy spots would be similar to the monthly visits some Jews make to the Tomb of Joseph near Nablus today - at midnight, in heavily armored buses, under IDF protection from a hostile population.
Under Israeli rule, Muslims have access to their holy spots. Who can credibly claim that the converse would be true under Arab rule? We already know how it was the first time.
If Jerusalem is split again, it means that the split will be an international border. Walls and fences would be built, checkpoints erected, buildings and streets divided, and people forced from their homes. This is inevitable, and anyone who believes that people can stroll from one section to another freely is lying.
Who in their right mind thinks that this is better than Jerusalem is today?