Especially for believers (in some God/higher power/religion)
What does a testimony mean (doctrinally or to you) in Mormonism? How does that compare or contrast to what a testimony means in another religion? (Other Christianity, some other religion, whatever)?
Did it change from you when you switched to Mormonism (for converts)? Did it changed when you switched out of Mormonism?
A testimony in mormonism relates to the restoration. I once got called out in public in testimony meeting because I did not say the church was true or that Joseph Smith was a prophet. I did say that I was happy to be part of a church that had such fine programs for the youth as I was a part of the young women's program at the time. I really did not know that a testimony was so narrow until I was called out, which was embarrassing. In the Christian church I belong to now there really isn't anything with the name testimony per se. One has faith, it is not presumed that one can have sure knowledge of anything. We stumble along the best we can with love as our goal.
I think the concept of testimony varies a bit among the different Christian faiths. I'm a Methodist and have never given a testimony at church. It's not something we do. Like joan99 says, in my church it is kind of assumed one has faith.
I have a friend who belongs to a Southern Baptist church and they do talk about their testimonies. I remember her writing one out for a Sunday School class she was in. She doesn't like public speaking, so the thought of standing up in front of a bunch of people and talking about how she came to believe in God made her very nervous.
From what I can tell, there are lots of flavors of testimony. Some are more similar than others. I've found Mormon testimonies to be most like Baptist, Muslim, and Jehovah's Witness testimonies, as far as what the people actually describe experiencing.
It shows lots of testimonies from various religions, some of whom there is NO WAY a Mormon could agree with. Still, they are just as strong, and just as heartfelt.
At my old job, I once had a client testify to me when he was picking up his order. It was awkward. This guy was clearly either a Baptist or Pentecostal or a non-denominational evangelical. He was totally nice when he did this, but it was just weird.
When I was younger, me and my friends used to classify the "testimonies" on Fast Sundays. Most fell into either "thank-amonies" or "story-monies." Some were "preach-amonies" or "cry-amonies" too. Just depended on what people felt like sharing that day, but they almost always ended with the classic, over-arching "I know the church is true" catchphrase. As long as you ended it with that, you were good to go.
"Testimony" is one of those words that means something very different to insiders. And sounds pretty innocent to the mainstream who don't realize what it means to insiders.
Testimony is weird way (to me) to say "faith". Faith is an interior thing that you can express or not. Testimony sounds kind of salesmanly like. Do you have a rap or spiel or routine to present about God? It is weird but it is not as weird as to use the word "witness" as a verb that means "to tell people about stuff in an ancient book".