Faith? Positive Thinking?

For a long time I wondered what the difference was between "faith" and "positive thinking". I still am not quite sure that we haven't been given power to bring things about with creative words - literally creative i mean. Someone pointed out on a forum that faith itself isn't the power, it's the one in whom we have faith. Good point I think but it still could be that we have more power than we use, just need the right perspective on it. We are often exhorted to meditate on good and noble things, keep our thoughts in control; perhaps constantly concentrating on a desired outcome really can make things come to pass.

THEN

Tony on Seeking Things Above posted about seeing a familiar passage in scripture in a new light; I read that then went to Ima Blogger where Tony C. (different Tony) wrote:

The inspiration of the Holy Spirit is astounding as the Bible warns us of such a practice: “But when ye pray, use not vain repetitions, as the heathen do . . .” (Mat. 6:7). For example, many motivational/success tapes, lectures, and seminars start you off by helping you make your thoughts repetitive.

I always thought of 'vain repetitions' as referring to drawing attention to oneself as discussed in the two previous verses. They're actually separate though, that's clear from verse 8 which says, "...for they think they will be heard because of their many words." This is my example of seeing something completely new in a familiar passage, why didn't I see that before?