The emphasis is on the sincerity of the believer, rather than on what he or she actually believes. Pluralism is very tolerant. It tolerates all kind of beliefs, even though they may contradict one another. There is only one kind of belief that it will not tolerate, and that is, the belief that doesn't tolerate other beliefs. You can believe whatever you like, except you must not believe that others are wrong in their belief.
Pluralism goes hand in hand with relativism.
Relativism is the idea that all things are relative. There are no absolute truths. What is true for you may not be true for me. It's all subjective. It is important that we understand Pluralism for several reasons.