I've always found it curious that Paul's letter to the Romans seems to be made up of two distinct halves. Chapters 1 to 11 are full of the massive and deep theology concerning God and his sovereignty. Then you get to chapters 12 - 15, which seem to shift gears and go into the minutiae of how to live our daily lives as Christians. The shift seems so abrupt.
But listening to a sermon by John Piper made me realise there is no abrupt change in Paul's discussion but the latter chapters of his epistle are a result of verses 33 - 36 in chapter 11. These verses are a doxology. It is Paul (and us if we have understood God that way he does) worshipping God, acknowledging that God is sovereign and all-powerful and almighty and in control of everything and that he chose to reach down and save us. And we are stunned by what God has done that we are speechless and our best response can only be: "Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are are his judgments and how inscrutable are his ways!" (Romans 11:33, ESV)
We who can say these words as our own, will therefore live out our whole lives as an act of worship to glorify him. In light of what we know of God (from Romans 1-11), Paul now asks us to be a "living sacrifice" (Romans 21:1). We will worship him with our whole lives when we understand God's sovereignty over all history.
That makes sense to me. Having been awed by God, how can we not turn away from our sinful lives and want to sacrifice ourselves daily for his glory. We can live as Paul describes in Romains 12 - 15 only if we fully grasp the preceding chapters.
For myself, I can see the connection between how I live my life and how much awe I have for God. When I wander from him and fail to reflect on his sovereignty, I fail to live the 'Christian life'. But when I come to him daily and seek his face and come to appreciate and understand his majesty and sovereignty, my mouth is shut, I am humbled, I am awed and I will do whatever it takes to glorify him in my daily living. That's the lesson I'm learning over and over. Be in awe of God and you will naturally submit yourself to him and use your life to glorify him.

