Speaking the truth is important. As with anything so important, there are concerns to be aware of. One is that most of us overestimate how much of the truth we possess. A second is that speaking the truth can do harm, e.g. when using it to blast people who don't yet see it—they necessarily become defensive and then the cause of truth is set back. A third is that truth has a lot of energy and if you drop it like a bomb on the playing field, you damage the space in which we're trying to explore the truth together.

The one who knows more has greater responsibility. Two unhelpful ways to speak the truth are to yell it out because it's frustrating to see something that other people don't, or to provoke people with it. The first is venting and the second is trolling, and both are incumbent on the truth-bearer to resist. If you do them, you discredit the truth you're trying to show.

Take this into account and there will be a bonus benefit, too: in cases where you don't really know as much of The Truth as you believe you do, you'll do less harm.