Obedience is a form of thankfulness. It's the same sentiment we hear in John 14:15 when Jesus says, "If you love me, obey my commandments." But it's not about a personal striving to be perfect; the next passage of verses talk about the promise of the Holy Spirit.
Permission to speak frankly? Sometimes around NCC, I hear people talk about how the sermons are not deep enough, expository enough, intellectual enough, Biblical enough, etc. Besides the fact that I think that is an absolutely ridiculous statement, my response is always, "Are you putting into practice those things you've already been taught?" For some people-- people like me-- it's easy to hide behind knowledge. That can be dangerous because knowledge without obedience puffs us up (1 Corinthians 8:1). I agree with Pastor Mark that most of us are educated beyond our level of obedience.
I'm not saying that we should not teach and preach more and more of the Word of God until we have what we know "down." Because that will never happen. What I am saying is that we should not walk out of a sermon only intellectually processing what we've heard. We should also walk out asking, "How does this change my life? What did I learn today that requires obedience in some area? How can I thank God through my words and actions?
Have we ever thought about obedience in terms of thankfulness? How might that change our views of obedience?