To Remember: Our God is an awesome God
Matthew 17:19-20 "Then the disciples came to Jesus privately and said, 'Why could we not cast it out?' He said to them, 'Because of your little faith. For truly I tell 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; and nothing will be impossible for you."
Luke 17:5-6 "The apostles said to the Lord, 'Increase our faith!' The Lord replied. 'If you had faith the size of a mustard seed, you could say to this mulberry tree, 'Be uprooted and planted in the sea,' and it would obey you.'"
Jesus gave His disciples the ability to heal people of all sorts of diseases, to prove to men that their message came from God. One man brought a demon-possessed child to the disciples. They should have been able to cast out the demon, but they could not. When Jesus cast out the demon, they asked Him why they had failed. He answered that they didn't have enough faith. If they had faith the size of a mustard seed, they could do anything.
A mustard seed is very, very tiny. (Show one if you can). But once planted, it grows into a plant large enough to provide a valuable food and shelter for animals. Jesus said a little faith can have incredible results. Who were the disciples to have faith in? God. And is there anything God can't do? No. Were the disciples actually causing the miracles, or God? God was. The disciples thought casting out a demon was too hard for them. Of course it was. They in themselves didn't have that ability. But can God cast out a demon? Of course. Can God do anything we ask of Him? Absolutely. So when we doubt, we are doubting God's ability. That is an insult to Him.
We don't need a lot of faith - just as much as a mustard seed - to provoke great results - because our God is an awesome God! We must believe in Him and not worry about what we can or can't do. God will not ask us to do more than we can. He wants us to be willing to do His work. He'll provide the rest. James says (5:16-18) "Therefore confess your sins to one another, and pray for one another, so that you may be healed. The prayer of the righteous is powerful and effective. Elijah was a man like us, and he prayed fervently that it might not rain, and for three years and six months it did not rain on the earth. Then he prayed again, and the heaven gave rain and the earth yielded its harvest."
Will God do everything we ask of Him? Probably not - because we don't always know best and He does. Jesus taught us to pray "Not my will but yours be done." Luke 22:42. God wants what is best for us and will provide it, sometimes against our (misdirected) wishes. James says in 4:3 "You ask and do not receive, because you ask wrongly, in order to spend what you get on your pleasures." He also warns that a doubter will not receive his request: "James 1:6-8 "But ask in faith, nothing doubting, for the one who doubts is like a wave of the sea, driven and tossed by the wind; for the doubter, being double-minded and unstable in every way, must not expect to receive anything from the Lord." Does any of this negate God's ability to do anything? No, He is all powerful.