Notes from Mark 11:22, 23
The kind of prayer that moves mountains is prayer for the fruitfulness of God's Kingdom. It would seem impossible to move a mountain into the sea, so Jesus used that illustration to show that God can do the impossible. God will answer your prayers but not as a result of your positive mental attitude. Other conditions must be met: (1) You must be a believer; (2) you must not hold a grudge against another person; (3) you must not pray with selfish motives; (4) your request must be for the good of God's Kingdom. To pray effectively, you need faith in God, not faith in the object of your request. If you focus only on your request, you will be left with nothing if your request is refused.
Notes from Hebrews 4:16
Prayer is our approach to God, and we are to come "boldly." Some Christians approach God meekly with heads hung low, afraid to ask him to meet their needs. Others pray flippantly, giving little thought to what they say. Come with reverence because he is your King. But also come with bold assurance because he is your Friend and Counselor.