Most believers have no clue about Biblical doctrine. Barna's survey showed only 9% of born-again Christians actually held a Biblical worldview, and the criteria was very basic:

1. Do absolute moral truths exist?
2. Is absolute truth defined by the Bible?
3. Did Jesus Christ live a sinless life?
4. Is God the all-powerful and all-knowing Creator of the universe, and does He still rule it today?
5. Is salvation a gift from God that cannot be earned?
6. Is Satan real?
7. Does a Christian have a responsibility to share his or her faith in Christ with other people?
8. Is the Bible accurate in all of its teachings?

Lord only knows how few would have correctly understood Biblical tithing, divorce, or eschatology. I've blogged about how dangerous it may be to deny the Word of God or even portions of it, yet this is exactly what happens when believers shirk their duty to know it.

Why is doctrine so important (besides the obviously direct commands to know the Word)? As an example, the "Jesus" of Mormonism is not the same Jesus of the Bible. Mormon "Jesus" marries, had kids, moved to America, and was not one with the Father. He was merely the local savior to this local world, brother of the devil (also a son of the local god). Mormon "Jesus"' father is not The God but merely a god, and any good Mormon can earn similar godhood and reign over his own planet (having spiritual sex with many wives and populating his world). Without a proper understanding of Biblical doctrine, Mormonism can appear to be just another denomination of Christianity, when the truth is far from so. How many Mormons are damned because of their [willful] failure to know the Word and correctly understand the basic doctrines of Jesus' nature?