"The major theme which marks out Paul's theology of God's people as renewed by the Spirit is the renewed call to holiness. It is a holiness not defined by Torah [OT law], and yet in much of what Paul says he can draw upon Torah for outline guidance... It is, as the prophets always wanted, a holiness which comes from the heart; and it is a holiness which ought to make the pagan nations see who the living God really is. It is in other words, not simply a matter of 'now you are saved, this is how to behave'; it is a matter of the genuine humanness envisaged as God's will for Israel being attained through the Spirit by God's renewed people. It is summed up well at the start of Romans 12, in the appeal for self-offering and transformation trough the renewal of the mind, resulting in the mutual upbuilding of those who, though many, are one body in the messiah."
[Source: N.T. Wright, Paul in fresh perspective, Fortress 2005, p124]