Which is the secret of its popularity, and perhaps what made Christianity so widespread. Since the more vague and open to interpretation a religious book is, the more people it will appeal to, you can find whatever you want there, yet still claim the authority of god, tradition, or the imagined wisdom of respected prophets to back you up.
It is a document seemingly ideally suited to precisely that use, one might speculate that it was compiled with exactly that purpose in mind... if one was either a heathen cynic or an ambitious priest.