There is a belief around the world that if a group, church, or individual calls themselves a Christian, they automatically are a Christian. That does not necessarily mean that they are. There can only be one true definition of a Christian, not several. The word “Christian” is found three times in the New Testament. They are Acts 11:26, 26:28 and I Peter 4:16. It is not mentioned in the Old Testament because there were no Christians then. There were people in the Old Testament that believed in God, and obeyed God’s word. But believers were not called Christians until Acts 11:26 which says, “The disciples were called Christians first in Antioch.”
People have the idea that just because they read the Bible once in a while, or attend a church sometimes, or have been baptized by sprinkling or immersion (which is the only scriptural method - Acts 8:27-40, Matthew 3:13-17), or have joined a church, or live a good moral life, that means they are a Christian. That is a very false assumption.
I have talked to people who have told me that they are not a Christian, yet they read the Bible. There are atheists that read the Bible, perhaps seeking for the truth, or trying to find mistakes in the Bible, or to find ways to combat Christianity.
Notice that the word Christian has the word Christ in it. So there could not be Christians before Jesus Christ founded it. That same is true about Mohammedanism.
The truth of Christianity is clearly found in the King James Bible:
A Christian is a person: