(1) Absolutes: which define core doctrines
(2) Convictions: which sometimes create different denominations
(3) Opinions: which are so subjective that people generally don't bother to divide over
(4) Questions: unsettled matters.
So, for example, Christians and Messianics are united in the same family as Believers because we both believe certain fundamentals (e.g. the Deity of Yeshua, the Inspiration of Scripture, etc).
Yet there are divisions in the family (unfortunately)...
- Christians believe that the Sinaitic Torah has been abolished; Messianics believe it is valid.
- Christians believe that the New Testament is anti-Judaic; Messianics believe that the Apostolic Writings are pro-Judaic.