What does separation of religion and state mean?

Yes, although it is hardly an easy task. Many countries have separated church and state. They either have seen the dismal result of their own theocratic history or else they look to such countries as Iran and Saudi Arabia today where religion is a compulsory part of society and law.

A truly free society must separate the two, for religion is a personal belief and should never be a part of any government that serves all citizens.