The gospel was restored by Joseph Smith, the Prophet, who saw two personages, God the Father, and His Son, Jesus Christ. God is not the author of confusion; therefore, He could not have one faith is all of them disagrees about essential points of His doctrine. There was a need to restore what Jesus Christ taught, and established.

Anyone, with a sincere, honest, humble, meek, and open heart, who reads the Book of Mormon will see and know that it does not contradict anything in the Bible, but it clarifies, explains, in simple and plain statements, and it establishes what the Bible said. It's the second witness of God to men. 

"With respect to James 1:5... which has been consistently ignored by LDS people, it would appear. By grace are ye saved, through faith, not of works lest any man should boast vs. You are saved by grace after all you can do, for example."

We believe in faith, and our behavior and doings are the fruits (works) of that Spirit that works in us; again, you're incorrect about what we believe. Why Jesus did the works He did? Why did His followers? Because TRUE faith produces works that are good in the sight of God; we do in humbleness and in meekness, recognizing Him, not us. It's by the grace (Atonement) of Jesus Christ that at the end we are saved indeed.

If we have ignored as you said about grace, have you ignore what James said in chapter 2 of his book about faith & works?

14 ^aWhat doth it profit, my brethren, though a man say he hath ^bfaith, and have not works? can faith save him?

Proverbs 4

7 ^aWisdom is the principal thing; therefore get wisdom: and with all thy getting get ^bunderstanding.

"...Some were contending for the Methodist faith, some for the Presbyterian, and some for the Baptist..." Wait a minute-those are all the same faith.  The Christian faith.  Apparently Smith did not know about the invisible (as opposed to visible) church.  According to the Bible, there is "one faith, one hope, one baptism." There are, of course, minor differences between the three denominations of Christianity listed above.  But they are only minor differences within Christianity not different faiths.  They are Christian denominations.  Should we stop using money because it is divided up into various denominations?  Mormonism, like Protestantism, also has many denominations.  Should we reject LDS teaching because of those other Mormon groups?

"Know ye not that Satan himself presenteth himself as an angel of light?"

The Gospel was not restored by Joseph Smith.  We know this quite easily by comparing the teachings of the Bible with LDS teachings.  What Smith taught is diametrically opposed to what the New Testament taught.  In order to restore the original gospel he would have to go back to the New Testament teachings not change them.  And textual critics have reconstructed precisely what the New Testament taught so one cannot appeal to the alleged plain and precious promises having been deleted therefrom.

There are no apostles today because an apostle, by definition, had to have seen the risen Lord.  Nobody after Paul, so far as I know, has seen Him.

With respect to James 1:5, God has already given wisdom in the Bible (not completed at its-the Epistle of James-writing) which has been consistently ignored by LDS people, it would appear.  Does God need to reveal what we already have in the Bible?  If we get new revelation which contradicts old revelation then we cannot really have new revelation.  By grace are ye saved, through faith, not of works lest any man should boast vs. You are saved by grace after all you can do, for example.

I concur with Elder Joseph B. Wirthlin thoughts concerning his attention was receiving revelation directly on many anvenues of the gospel.