God & Humans, the response (then & now)

I am in a One Year Bible reading plan. Last night, the two primary passages I was reading was Exodus 2:11 - 3:22 and Matthew 17:10-27. The Old Testament piece describes Moses' burning bush experience and the New Testament segment sees Jesus instructing Peter to pay the temple tax with a coin from the fishes mouth.

In the first, God speak to Moses in a burning bush and says to him...what? "Take off your sandals, for you are standing on Holy ground." Now I have read and heard some very interesting commentary on that single verse, but that is not really where I am going here.
The point is that God spoke. Scripture doesn't confirm the action of Moses, other than to say that "...he hid his face in his hands...", but we can assume that he followed God's instruction and removed his sandals.

In Matthew I want to focus on a verse that is actually just ahead of the temple tax story. In 17:17 Jesus says, "You stubborn, faithless people! How long must I be with you until you believe? How long must I put up with you?

Now lets establish a little timeline. The burning bush story occurred about 1420 BC. Here we are in 2009 AD. Matthew 17:17 is just about in the middle, give or take a few hundred years...
Scene one, God spoke, human listened. Scene two, Jesus spoke, humans refused to believe. Scene three, God, Jesus and the Holy Spirit are speaking to your heart every day, what are you doing? Are you removing your sandals daily? Or are you left wondering, "Why couldn't we cast out the demon?"