In a talk recently given by Elder Holland, he talked about the importance of belief. Thank heavens. The reason why I rejoice is because I personally have a hard time with the phrase "I know." I have my personal doubts and areas where I lack knowledge and experience. Absolutes like "I know" scare and seem too final. Plus if I truly knew, wouldn't I be at risk of the sin against the H.G.?
I have always felt the pressure to "know". It's dogmatic in our culture. As a missionary, I was taught to say "I know", not "I believe". To take our testimonies to the maximum seems to be the expected norm. I was curious about this "norm" and decided to take some data on it. During fast and testimony meetings I kept a tally of certain phrases that were used. For example, I monitored how often someone would say "I know Joseph Smith was a prophet" or some similar variation. I kept track of the "I know", "I'm grateful", "I bear testimony", and "I believe". I also kept track of the topics such as Jesus Christ, the Atonement, the Book of Mormon, prophets, prayer, and etc.
I did this at least 10+ times over the course of a few years and came out with a few insights. For one, I noticed that YSA wards tended to express more gratitude than older family wards. Mostly though, I noticed the lack of the use of "I believe." In all of those testimony meetings, I probably heard the phrase I believe less than 5 times. Half of them were by my roommate who knew what I was doing and used them just to skew the numbers. The use of "I know" and "I testify" was roughly even in use, garnishing around 15 uses a piece each meeting.
This long observation solidified that there is a cultural tendency to use "I know" instead of "I believe." For many, this is not a big deal and the difference between the two words is moot and irrelevant. For me, I prefer the term believe because it implies hope, faith, and a bit of uncertainty. It's vibrant in its color of meaning and emotion. While the word KNOW is powerful, immovable, and certain; which doesn't convey my actual feelings. I don't think it conveys most people's actual testimony.
Due to this cultural norm I have long felt less spiritual or that I had less of a testimony because I didn't feel comfortable using the phrase "I know" whilst everyone around me did. It always struck me as ironic when the declaration of belief was never used and yet we would sing "I believe in Christ" at the end of the meeting.