Book of Mormon - Is it true?

I had the Mormon missionaries round recently. We got to talking about how we know what is true.

The Mormons cited the Book of Mormon:

"And when ye shall receive these things, I would exhort you that ye would ask God, the Eternal Father, in the name of Christ, if these things are not true; and if ye shall ask with a sincere heart, with real intent, having faith in Christ, he will manifest the truth of it unto you, by the power of the Holy Ghost. And by the power of the Holy Ghost ye may know the truth of all things." (Moroni 10:4-5)

And how does the Holy Spirit do this? The answer came from Doctrine and Covenants 9:8-9 (another LDS scripture). It says,

"But, behold, I say unto you, that you must study it out in your mind; then you must ask me if it be right, and if it is right I will cause that your bosom shall burn within you; therefore, you shall feel that it is right. But if it be not right you shall have no such feelings, but you shall have a stupor of thought that shall cause you to forget the thing which is wrong; therefore, you cannot write that which is sacred save it be given you from me".

In other words, if it feels good - it's right. It sounds simple, ask God and He'll make you feel good if it's true. But, then what of people in other religions who feel good about what they believe? Are feelings a good way to test truth claims?

The Bible says

"Look to God’s instructions and teachings! People who contradict his word are completely in the dark." (Isaiah 8:20)

This makes sense; if we are convinced the Bible is true, then we know that those who contradict it cannot be teaching what comes from God. Mormons believe that there are many "gods". God has parents and siblings who are also gods. Yet the Bible says,

"You have been chosen to know me, believe in me, and understand that I alone am God. There is no other God - there never has been, and there never will be." (Isaiah 43:10)

So, according to Isaiah 8:20, where is the Mormon Church on the issue of how many "gods" exist? Isaiah says that it is completely in the dark.

The Book of Mormon also makes an interesting, and testable claim:

"And the angel of the Lord said unto me: Thou hast beheld that the book (the Bible) proceeded forth from the mouth of a Jew; and when it proceeded forth from the mouth of a Jew it contained the fulness of the gospel of the Lord, of whom the twelve apostles bear record; and they bear record according to the truth which is in the Lamb of God. Wherefore, these things go forth from the Jews in purity unto the gentiles, according to the truth which is in God. And after they go forth by the hand of the twelve apostles of the Lamb, from the Jews unto the Gentiles, thou seest the formation of that great and abominable church, which is most abominable above all other churches; for behold, they have taken away from the gospel of the Lamb many parts which are plain and most precious; and also many covenants of the Lord have they taken away." (1 Nephi 13:24-26)

The claim is that the Bible has been deliberately corrupted by the early Church resulting in the loss of "plain and most precious" things. This means that we need a restoration of the truth - which is where the LDS scriptures come in. Without that corruption everything the Mormon believes is meaningless. So is it true? The Book of Mormon footnotes claim this was first written around 600-592 BC. Leaving aside the fact that there is no evidence to support the Book of Mormon's existence prior to the 19th century, we can test this claim. And the Bible says we should. It asks an important question:

"How will we know whether or not a prophecy is from the Lord?" (Deuteronomy 18:21)

Good question! The next verse answers the question:

"If the prophet speaks in the Lord’s name but his prediction does not happen or come true, you will know that the Lord did not give that message." (Deuteronomy 18:22)

This is genious - it's so simple and it confounds self-fulfilling prophecy! So, if Nephi is a false prophet there may be some of his predictions which would not come true. And this is one of them! We know from the Dead Sea Scrolls and over 40,000 manuscripts for the New Testament, that the Bible has not been changed.

Conclusion: Mormonism fails the tests of doctrine, factual accuracy, and the test of a prophet. Doctrinally it contradicts what God has already said. It has no historical basis before the 19th century. Even if it did, the Book of Mormon fails the test of a prophet. Mormonism is therefore not from God.