Are you a 'True Buddhist'?

I was told recently that President Obama is a 'cultural Christian' as opposed to being a "True Christian" because he was born to a Muslim father and 'had' to follow the religion of his mother's family. The fact that he might sincerely and faithfully believe in God and Jesus does not matter.

This led me to think: "what makes a 'true' Buddhist?", in other words: how does one 'define' a Buddhist?

Do you need to believe in Buddha? If so, which Buddha? Gautama Buddha? Amitabha Buddha? Maitreya Buddha? What if you also believe in Guanyin/Avalokitesvara Bodhisattva?

Do you need to belong to a tradition or school? If so, which school/tradition? Theravada? Mahayana? Vajrayana? Buddhayana?

Does your personal practice define you as a "True Buddhist"? What if you are a Nichiren monk or nun? What if you believe in and focus your practice to reach Western Paradise? What if you do not believe in the 31 planes of existence and that they are frames of mind rather than planes of existences? What if you only practice meditation in accordance with Anapanasati and Satipathanna Suttas but not the 4 Brahma Viharas? What if you practice only the 4 Brahma Viharas?

I think all of the above questions doesn't really matter; what matters is "Does it bring about the end of Suffering?" i.e. the fulfillment and complete understanding of the 4 Noble Truths...maybe. I don't really know. Maybe I'll find the answer when I'm enlightened.