Please reread Mk 11:23, and show me, if you can, where Jesus tells us to ask God to move the mountain.
Now if you read the next verse you will see where Jesus tells us that whatsoever we ask for believing, when we pray, then it will be given.
I shouldn't have to say this but there is more than one kind of prayer. For example, there's a prayer of Thanksgiving, prayers of intercession, and just like in verse 24, there is a prayer where we just ask God for things.
However I would like to point out that verse 23 is not praying to God but speaking to the object or thing, while verse 24 is praying to God and asking him for whatsoever, and it is written that it shall be given, and I stress the word shall, because if God said, maybe, then you don't know what He will do, which means there is no solid ground to stand on concerning that promise. It would be like laying your foundation in sand rather than in the rock. And it would also cause you to Hope and wonder rather than have faith for God to give or do something about the situation you're praying for.
Back to verse 23. Why would Jesus himself teach us to speak to objects in faith, like he did, if he did not want us to do it?
I am not the first one to come up with this word of Faith theology, Jesus is. And I am just following His lead, and that which is written.