This is an easy one. 

Would you want to believe you've won the lottery or want to you know you've won the lottery? There's a bridge of uncertainty involved when it comes to believing but, you are standing on solid ground when you are knowing.
Try this. The reason why we wear seat belts is that we believe we could be in an accident because, we know if we are, it won't be a good thing. Ever hear about athletes being in the "zone" and that's how they won the game? That’s because they already know they won even before the game started. That's the kind of thinking you need when you make that decision to change your life for the better.
Believing that you are going to reach your goal aint gonna cut it. You got to know it.

Y'NEVANO how strong you can be.