Some believe that the Bible is the word of God because it was literally told to the authors by God himself, and therefore is infallible. Others believe that the Bible was inspired by God and, although it can contain errors of history and science, it is infallible on matters of faith.
There is no evidence of either. The Bible contains many errors of history and science, and is therefore not infallible. It contains many contradictions and inconsistencies on theology, and is therefore not even infallible on matters of faith.