Whoo! It has been hard lately finding time to post. I will try to get something out on lesson 25 later today or tomorrow. In the mean time, here is a post I did a few months ago on Priesthood and the Power of Godliness, which also refers you to an old post at Mormon Matters.
I have not read all the references extra-carefully to confirm this, but I think the title of this lesson does not appear in any scripture reference in the materials. Does anyone think that is interesting?