As I've gotten older, I've decided that "witnessing" can be taken literally. As in, "This is my faith, and it works for me, and this is why." Thus, bearing witness to your own faith experience. Whether or not your audience is interested in pursuing that faith for themselves is up to them. So I think it IS possible to believe your faith is correct, without making others feel like pond scum. There are many areas where people believe they are correct (political, social policy, health benefits of a particular diet) -- and if I think I'm right, I may think you are wrong, but we can't all be right about everything. If we can respectifully disagree, I think we can learn from one another, and enrich one another. And if people are NOT allowed to believe something, that is in itself a boundary violation -- because really you are saying that a partciular brand of belief is the correct one and if I don't hold that, then I am wrong, and we're right back where we started from.