As some translators have admitted, the art of translation is partly to blame for making Plato more difficult in English than he is in the original Greek. Fortunately, as this Website shows, there are solutions that can resolve much of that problem. Aside from the translation difficulties, there really are some complex thoughts in the Republic . Then again, virtually any religion or philosophy has its difficult concepts. There does not seem to be an alternative to that.
Life is much too interesting and complicated to fit within a simple guiding principle.
The difference between Plato and a religion may be, primarily, that religions pace themselves better. We start, in a religion like Christianity, by raising our children with the simple stories. We then introduce them to discussions of how they might apply Biblical principles in different situations. Members of the congregation listen, weekly, to explanations of how those principles apply to everyday life. We baptize our infants, marry our young couples, and bury our elderly under the banner of the religion.