Faith as a Mustard Seed

So in the bible christ tells you that if you have "faith as a mustard seed" you will be able to move mountains. Have you ever seen a mustard seed? It is so small that if you tried to put it between your fingers you would be unable to do so without your fingers touching. I always wondered if that was all the faith you needed, then how come none of us could move mountains? Did we honestly not have faith enough to keep our fingertips from touching? It took me awhile and a good explanation for me to understand why Christ used the mustard seed as an example. When Jesus spoke about the mustard seed he was not referring to its size, rather its capacity. Being an Indian I (or at least my family) use the mustard seed for everyday cooking uses. Many a times I have seen my grandmother put the mustard seed in hot oil and I have had to step  back because the oil would pop due to the mustard seed. The reason for this is that the mustard seed is so compact there is no room for air so when it hits the oil it pops. Even an Athiest has faith the size of a mustard seed, but it takes a fervent christian to have faith enough for there to be no room for doubt. That is my prayer. I feel in the past couple of days/months I have been lacking in the faith department. I hear God's promises but feel as if they are not for me, or maybe I am exceptiong. I find myself to be a doubting Thomas. Is that really what God said? Was God speaking to me? So I ask for faith in my prayer. For something that will afirm my faith and keeping so compact with faith that there is no room for any doubt. May these words be of use to you. Thank you