The word “Christian” is a trasliteration in Act 11:26. Acts 26:28 should be translated “Messianics?” (Punctuation was not in the origional language). We should thus see both the inclusiveness of the promices of God in that Christianity is for Jewish and Gentile alike (all peoples); and see Christianity’s exclusiveness in that its promices, comands, and precepts define and limit who can claim the name “Christian.” Our problem today is that the word “Christian” has been relativized because people want to be inclusive instead of defending Biblical exclusivism. So if you dare say that someone is not a “Christian” you will be criticized. You will be citized by those who claim not to jugde others.
But there are essentials that will place people outside of Christian orthodoxy because religious people are genuinly lost. For example, all the “omni” attributes are essential to a orthodox understanding of God. Denying an attribute such as omniscience as Open Theology does, shows the lost state one is in. This is why the fields of Christian appologetics, philosophy, & theology have always proclaimed a gospel that excludes until reciently. Christians theologians use to affirm that there are certain truths that cannot be denied to be a Christian. Therefore if you were a Roman Catholic, Morman, Jehovah Witness, Eastern Orthodox, ect. you were not a Christian because you deny essential Christian doctrine (which I believe is still true). The problem today is that we are judged for being judgemental in saying the same thing. The only heracy is believing that heracy exists and there heratics.
All this is why the book of Job is so important because it give the basis for the necessity Christian exclusivism from the very beginning. The friends of Job sat around talking and God speaks out of the tornado and says, “you are liars.” Job shows us that Man left to his own resources gets it wong all the time. Today, Job challenges us to define essential foudations for the Christian World and Life view.