What has a strong meaning...being positive or being sure?!

What has a strong meaning...being positive or being sure?

I know both mean pretty much the same thing...but does one have more meaning than the other? What do you think?

I'm reading a book right now called The Secret. It's all about the power of thinking. It's amazing and quite an eye opener. My friend's brother recommended it to him and then he to me. According to The Secret, positive thinking has a stronger meaning. What I have read makes a lot of sense. If you're really interested, check it out. I don't have it right now to tell the author's name, but it's a fairly new book. I'm sure any major bookstore could help you find it.