I know of no other scripture that can radically change the way we pray the way that Mark 11:23-24 can. In these few lines Jesus tells us point blank that *we* have the power to *speak* into situations and remove the obstacles (mountains) that not only stand in the way of fulfilling our purpose in Him, but in our own, personal lives. He doesn't define what kind of mountains these are, which should indicate the inclusion of *all* mountains. Health mountains, money mountains, personal character mountains, career mountains, spiritual mountains - any and ALL mountains.
He follows this by stating that *whatever* (anything, all inclusive, ALL - there's that word again) we ask for in prayer and believe that we have *already received it*, we will have it. Note that this doesn't mean that we necessarily possess whatever it is at the time of prayer - although this is the standpoint of approach - but that IF we truly believe that we already have it, that we *will* have it. This can be difficult to wrap our heads around because it places the thing we're praying for not in the future, but in the here and now - already in our possession. This also leads us to pray from a thankful position, instead of a begging position. If someone hands you a bowl of ice cream you don't turn around and say "where's my ice cream?", because it's right there in front of you. You would thank them for the ice cream and dig in. (You can probably tell I've been dieting) The same is true with this approach to prayer. If God has already provided you with something, you thank Him - even though the tangible evidence of having it isn't there yet.
This doesn't call for a long, drawn out prayer either. It's very simple and direct. To use this formula in prayer might go something like this:
"I speak to (cancer, poverty, pride, etc) and I tell you that you have no place in my life. By the authority of Christ vested in me, I command you to go in Jesus name, now! Lord, I thank you for (whatever the mountain was blocking you from - good health, income, a new job, etc) and I receive it now in Jesus name! Thank you Lord."
That’s Optimistic Trust.