The purpose of a Notary is really to be a second witness. In most cases they verify that something is accurate; in this case I am who I said I am.
That got me thinking about the scriptures that say "In the mouth of two or three witnesses shall every word be established."
There are 6 scriptures which make reference to this phrase: Deut 17:6; Matt 18:16; 2 Cor 13:1; Ether 5:4; D&C 6 :28, D&C 128:3
I think it is very interesting that this phrase was repeated so often. It makes sense that two or three witnesses are stronger than just taking one person's word for it. It is interesting that not only is this stated in the scriptures, but it is also reflected in our modern culture.
Even from a logical view, it makes sense that the Lord would establish another witness(Another Testament) of our the Savior's life, words, and ministry. The Book of Mormon.
Book of Mormon itself contains the testimony of the three witnesses and the eight witnesses as further proof of authenticity.
This example of "two or three witnesses" is also another explanation for why missionaries proselyte in pairs. So they may both testify and witness through their testimonies of the truthfulness of the gospel.
In Alma 9:6 the people stated, "And they said Who is God, that sendth no more authority than one man among this people, to declare unto them the truth of such great and marvelous things?"
And then in Alma 10:12
"And now, when Amulek had spoken these words the people began to be astonished, seeing there was more than one witness who testified of the things whereof they were accused,"
I know that there are two witnesses of Christ and they both testify of Him. That He is who He said he was, the Only Begotten of the Father and the Savior of us all.