I remember C.S. Lewis writing somewhere about how some preachers like to use the word "we" when pointing out a problematic behavior. For example, consider the statement "We secretly judge the homeless man around the corner". If I recall correctly, he describes it as a potentially disingenuous way of accusing the audience of something while not sounding accusatory. Because after all, "we" includes the speaker, so it implies that the speaker is only being as harsh as he is on himself. However it can still come off as disingenuous because even though the speaker says "we", he really doesn't do the thing he's accusing his audience of, and most people don't imagine that he really does.
Of course, C.S. Lewis described it much more carefully and articulately than I have, which is why I'm trying to find the original reference in his works. Does this ring a bell for anyone who can help me find out where he wrote about this?