"This is the word of the Lord to Zerubbabel: 'Not by might nor by power, but by My Spirit,' says the Lord of hosts. 'Who are you, O great mountain? Before Zerubbabel you shall become a plain!" Zechariah 4:6-7a
"If you have faith as a mustard seed, you will say to this mountain, 'Move from here to there,' and it will move; and nothing is impossible for you." Matt 17:20
"Assuredly, I say to you, if you have faith and do not doubt... if you say to this mountain, 'Be removed and be cast into the sea.' it will be done. And whatever things you ask in prayer, believing, you will receive." Matt 21:21-22
"Jesus answered and said to them, 'Have faith in God. For assuredly, I say to you, whoever says to this mountain, 'Be removed and be cast into the sea,' and does not doubt in his heart, but believes that those things he says will be done, he will have whatever he says. Therefore I say to you, whatever things you ask when you pray, believe that you receive them, and you will have them." Mark 11:22-24
It isn't might that moves the mountains, it isn't even power, it is the Spirit of God, working through your faith, with no doubt. Prayer is communication, a relationship with God.
God + faith + prayer - doubt = mountains move!