Hmm…the concept I’m picking up in Romans 11 is a little new to me, but this is how I’m understanding it. Salvation was first offered to the Jews, but due to their rejection, any Gentile can also now receive salvation. In doing so, God brings glory to himself and fulfils Israel (remembering that now we are saved by grace through faith, not following the law). I have to say … that’s pretty neat. And therefore, it makes the first bit of chapter 12 make a whole lot more sense. Knowing that we are saved by the grace of God to fulfil his kingdom, why wouldn’t you choose to offer your life as a living sacrifice? As for the rest of chapter 12, I feel like it speaks for itself pretty well. You should go read it.