SteelEdge said:
Matthew 17:20 And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.
The only conditional part to me is the small amount of faith needed.
But the faith is the key. Faith, in the sense that is used through most of Scripture, is distinct from a propositional belief. It is a faith grounded in God. That is, it requires some knowledge of Who God is, and what His intentions are. It is not synonymous with, "trust," but one would do much better to think of it as trust than a propositional belief.
Consider the following statements:
1. I believe that the world is round.
2. I believe in SteelEdge.
The former is a proposition about which I have degrees of certainty. I say that I am more than 95% certain that the Earth is round like a ball. All the evidence points to it and I think that it is so. The second cannot be phrased in this way. If I believe in you, I certainly believe that you exist, but it's really another issue altogether.
In this sense, I can say that I believe in you and then ask you to do a thing. If our relationship has come far enough, you will do it. However, it is contrary to the very faith, itself, for me to ask certain things of you. If I ask you to do something contrary to your character, prepending it with, "I have faith in you," this becomes a non sequitur. I have some erroneous conception of your character or your will in which I made my petition. I have asked, "in bad faith."
When I relate to God, I bring my petition knowing that God is able to do that which He wills. It is in this sense of "faith" that Christ says, "If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you." I absolutely believe that God can move mountains. I believe that He will do so if I ask in faith.