I recently read a sermon of John Piper on Romans 12:1-2. Here is a few paragraphs on the importance of worship as the precursor to mercy.
"...today we notice something very significant in verse 1: before Paul describes our new life in Christ as merciful he describes it as worshipful. Before you think that the Christian life has everything to do with being merciful to people, realize that it has everything to do with being worshipful toward God. '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.' Before we give ourselves away in mercy to man, we give ourselves away in worship to God.
This is crucial to see. We must never let the Christian life drift into a mere social agenda. I use the word 'mere' carefully, because if God is left out, our mercy will be mere social agenda. We do no one good in the end if we are not worshipping and leading them to worship in the acts of mercy that we do. If our good deeds are not expressing the worth of God, then our deeds are not worship, and in the end will not be merciful. Making people comfortable or helping them feel good on the way to everlasting punishment, without the hope and the design that they see Christ in your good deeds, is not mercy. Mercy must aim to make much of Christ. For no one is saved who doesn't meet and make much of Christ. And not to care about saving is not merciful.
Therefore, it is absolutely essential that Paul put worship before mercy and that he define the Christian life as worshipful before he defines it as merciful. Or to put it more carefully, Paul defines the Christian life as worship so that it can be merciful. If we are not worshipping in our behavior—that is, if we are not making much of God's mercy in Christ in and along side our behavior—we are not giving people what they need most. And that is not merciful. A merciful lifestyle depends on a worshipful lifestyle. So before Paul defines Christian living as merciful, he defines it as worshipful. "
Read the whole sermon here: http://www.desiringgod.org/ResourceLibrary/Sermons/ByDate/2004/174_Present_Your_Bodies_As_a_Living_Sacrifice_to_God
