Evidence for God from Science

What are the important doctrines in Christianity to believe that make someone a Christians? I know you have to except Jesus as your personal savior but what other doctrinal truths are just as important. That if one didn't believe these doctrines then they can not honestly say they are a christian?

something like this
ex. Somebody can call themselves an Atheist but if they go to church and say they believe in god that doesn't make them an atheist. Or call themselves a vegetarian but eats meat. What doctrines in Christianity can is there that can also make a similar claim.

Only two rules to live by, Love God with all your heart and love your neighbour as yourself.
I really dont think there is much more to it as everything else stems from the above.