Christianity is the only true religion and it is most certainly Judaism perfected.
That’s YOUR belief.
Unfortunately, you have to live in a world with people who don’t share your beliefs.
...remember, after Christianity came Islam, and that religion appropriated Abraham, Moses, AND Jesus... so there’s yet another group who believe they have in fact the perfected religion.
The perfect religion is the one that is perfect for you but don’t force it on your neighbor.
None of the Abrahamic faiths believe we are without sin or have achieved “perfection”.