In Matthew 17.20, Jesus said to his disciples, "Amen, I say to you, if you have faith the size of a mustard seed, you will say to this mountain, 'Move from here to there,' and it will move. Nothing will be impossible for you." Again, in Luke 17.6, he said to the apostles, "If you have faith the size of a mustard seed, you would say to this mulberry tree, 'Be uprooted and planted in the sea,' and it would obey you." I've always been intrigued by what the Lord had said here ~ how can I get this faith the size of a mustard seed?
Once I actually challenged someone who had lost all his hair to believe in Jesus and assured him that his hair would come back after I prayed for him. Of course, nothing miraculous happened. Then there's the time I prayed for my son when he was near death, and he miraculously recovered. This time the petition just came forth spontaneously without any hesitation. Recall how Peter in his boat saw Jesus walking on the sea and wanted to do the same. Jesus said "come" and Peter got out of the boat and started walking toward Jesus. But he became frightened and began to sink. Immediately Jesus stretched out his hand and caught him, and said to him, "O you of little faith, why did you doubt?"
My new understanding of faith: (1) I cannot "force" myself to have faith. For example, it'll be utter foolishness to believe that I can go out and heal any sick person I run into. (2) Faith can work miracles only if you are doing God's will. If I get out of a boat on my own, believing that I can walk on water, it won't happen. But if Jesus had actually commanded me to do it, then I would do fine if I believed in him. (3) Conclusion: Do God's will always and trust in him completely while doing it. (4) Last, since faith is a gift from God, seeking union with him will definitely enrich this gift.