It’s not great faith you need; it is faith in a great God. Faith is like a window through which you can see something. What matters is not whether the window is six inches or six feet high; what matters is the God that your faith is looking out on. If it’s the creator God, the God active in Jesus and the Spirit, then the tiniest little peep-hole of a window will give you access to power like you never dreamed of. Of course, this cannot be used for your own whim or pleasure; as soon as you tried, it would show that you’d forgotten, once more, who this God really was. Humility once again.