Wikipedia has a lot of definitions of testimony, but I’m focusing here on the religious one, to declare testimony is to express one feelings of their faith, to describe often through personal experiences, why one believes what they believe:

In some religions (most notably Mormonism and Islam) many adherents testify as a profession of their faith, often to a congregation of believers. In Mormonism, testifying is also referred to as “bearing [sic] one’s testimony,” and often involves the sharing of personal experience—ranging from a simple anecdote to an account of personal revelation—followed by a statement of belief that has been confirmed by this experience. Within Mormonculture, the word “testimony”^[3] has become synonymous with “belief.”

A testimony is personal and individual and groundless in every other way except in one’s personal experience. Testimony is not based on scientific or historical evidence, rather, testimony is simply what happens when one experiences something transformational in one’s life. More specifically, testimony is something one gains when one is touched by grace. And grace is rooted in the atonement of Jesus Christ.

Adam Miller says it better in his book Rube Goldberg Machine:

A testimony is a bolt of lightning that splits the night in two. Testimonies contravene the stubborn inertia proper to this world. Here, the lost and impossible possibilities revealed by a testimony take hold of and recondition the world.

Testimonies are not essential because they reveal how things are in the world (this is the task of science). Testimonies are essential because they reveal, in light of the Atonement, how things can be.

Miller, Adam S. (2012-04-04). Rube Goldberg Machines: Essays in Mormon Theology (Kindle Locations 1444-1446). Greg Kofford Books. Kindle Edition.

Grace makes possible what was previously impossible, it transcends the limitations of this world and gives us the power to strive for something more. It allows us to transcend the limitations of our bodies, our weaknesses, our addictions, even our mortality, Christ’s atonement reaches through all of that and pulls out from within something divine and eternal. Our testimony, if it is anything at all, is simply this, our experience with grace.

Our testimony has nothing to say about the age of the earth, the nature of revelation, or the historicity of scripture.

This can be deceptive for many. Our sacred scriptures are rooted in stories and in history. The Bible begins with the story of the beginning of the world, stories of Adam and Eve, a global flood, incredible stories of Moses in Egypt. These stories are rooted in history, describing characters in nations that actually existed. The Book of Mormon is similar, audaciously so. Coming from the most humble of beginnings bursting forth soon after the birth of a nation, giving ancient America a biblical story. In 500 pages, the Book of Mormon runs through one thousand years of ancient American history.

Neither of these books are historical or scientific. Our experiences with them have nothing to do with what they are saying about history or science. These books were written and translated by holy men and women, not historians or scientists. When we bear testimony of them, we are saying nothing about our views of history or science.

The same follows for Joseph Smith, President Monson, tithing, the word of wisdom, the Church as an institution, etc. To have a testimony of these things is to have experienced the Atonement in connection with them—nothing more, nothing less. Who would be more horrified by the idea of people having a testimony of Joseph Smith than Joseph Smith? Who would be more horrified by the idea of people having of a testimony of the Book of Mormon than Mormon?

Miller, Adam S. (2012-04-04). Rube Goldberg Machines: Essays in Mormon Theology (Kindle Locations 1374-1377). Greg Kofford Books. Kindle Edition.

I think this distinction is important. When I see or hear about attempts to prove the historicity of scripture, I’m left cold. I don’t see the point, it feels like a waste of time and resources. It does a disservice to religion, science and history. We all have biases, granted, but science done right and history done correctly, requires the adherer to encounter the evidence as they find it and let that evidence lead them to conclusions that may even contradict what they may find in sacred works. It’s possible that neither the Bible nor the Book of Mormon are true historically, and certainly not true scientifically. But both claims are beside the point.

And the opposite is true for similar reasons. If we attempt to ground our testimonies in the realm of science, we are standing on shaky ground.

If we say the Book of Mormon is true because we believe it explains Native American history, what is left of our faith when we encounter evidence that contradicts this? Those who do tend to react in one of two ways, the reject the science or they reject the religion. But neither of these choices makes sense. Our hearts and our minds should be open to learn as much knowledge as we can possible get in this short period of our lives. We absorb it and are informed by it, our faith should be durable enough to grow right along with it.

What I’m trying to say is that our testimony in the church, in Joseph Smith, in the Book of Mormon have nothing to do with our present views on historicity, evolution, archeological evidence. The church has very little to say on these topics nor is qualified to do so. The church is for us, our scriptures are for us, our prophets are for us. They are spiritual tools to transform us, individually and collectively, and to bring us to Christ.

The Book of Mormon says it best here.

23 For we labor diligently to write, to persuade our children, and also our brethren, to believe in Christ, and to be reconciled to God; for we know that it is by grace that we are saved, after all we can do.