A Bible-believing Christian is a Christian who believes that all 66 books of the Bible are the Word of God, without error or contradiction. It is not necessary to believe that the Bible is God's Word in order to be a Christian. It is only necessary that a person be born again in order to be a Christian. (see What is a Christian?) However, it is necessary to believe that the Bible is the inerrant Word of God in order to live the Christian life and be classified as a “Bible-believing Christian.”
A Bible-believing Christian must believe that everything in the Bible is the Word of God and thus true. A Christian who only accepts parts of the Bible as being true is not a Bible-believing Christian. He may be a Christian—if he is born again—but he is not a Bible-believing Christian. Even if a Christian believes 99.9% of the Bible, and there are only a few verses that he does not believe, he is not a Bible-believing Christian.
There are many people who claim to be Bible-believing Christians. Even many so-called ministers claim to be Bible-believing Christians. If you talk to them they will tell you that they are born again and that they believe that the Bible is the Word of God, without error and without contradiction. But when you begin to question them on some of the various doctrines of the Bible, they then say that they don't believe this doctrine and they don't believe that doctrine. If the Bible says something, or if a particular doctrine is in the Bible, and a person refuses to believe it, then that person is not a true Bible-believing Christian. In order to be a Bible-believing Christian, you must believe everything and every doctrine that is in the Bible.
Some of the most obvious examples of this are the doctrines about water baptism, being filled with the Holy Spirit, the nine gifts of the Holy Spirit listed in I Corinthians 12:8–10, and what a minister of the gospel is. A person who does not believe what the Bible says about these things is not a Bible-believing Christian—even if they say that they are!