Watch for the word therefore. In an epistle especially, it is the hinge the whole letter turns on.
Paul spends eleven chapters of Romans laying out what God has done: creation, the fall, the law, sin, grace, the cross, the resurrection, mercy poured out on people who did not deserve it and could not earn it. Then chapter twelve opens with one word that changes everything that follows.
I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship.
Romans 12:1 (ESV)
Everything before that verse is the mercy. Everything after it is the response the mercy makes reasonable. Skip straight to the command and it sounds like one more thing to do. Read the eleven chapters that earned the word therefore, and the same command reads like the only sane response left.
Whenever a passage starts with therefore, stop and ask what it is there for. The answer is always sitting in what you just read.