In studying religions look for:

Basic concepts in each religion

It would be a good idea to make your own list of the important ideas, and the technical vocabulary, in each religion.   No list of basic ideas could ever be called “complete”, but there are some things that couldn’t be missed out.  Those are the things you are trying to find.

 The role of basic personalities in each religion

For example:

How far is Jesus seen as God by Christians?  Why?

Is Mohammed seen purely as a human being by Muslims? (Answer yes and no)

What is the role of the Buddha?  How is it different for different sorts of Buddhists?

In what sense are the Sikh gurus one spirit?  How do they differ?

Diversity within the religion. 

Why & how do followers of the same religion disagree?

 for example:

Different sources of authority:

            Shi‘a and Sunni Islam: the role of the Hadith

            Protestant, Anglican and Catholic Christianity: the role of Reason and Science

            The huge variety of texts, myths, and religious persons in Hinduism.

            The role of post-enlightenment scientific thought in Judaism

Different understandings of the role or value of that authority.

            Does the Bible contain divine rules, or merely values and principles?

                        e.g. Is divorce acceptable?  Must we burn witches?

Is Shari‘a law in Islam a set of unbreakable rules and punishments? or principles which can be re-applied?

Different ways of applying that authority to modern life

Some Jews refuse milk and meat at the same meal, because that is how they apply the rule “Never boil a kid in its mother’s milk.”  Others say this rule doesn’t prevent milk and meat being eaten together.

Seventh Day Adventists refuse blood transfusions because the bible says to “avoid blood”; but other Christians apply this rule differently.

Different leadership

            This is particularly important for Islam at the moment

There are other reasons for diversity as well.