Because of grace, there are no excuses for sinful living. Only, God is for us. Not against us. Too often we live the Christian life expecting ourselves to be more perfect then even God expects us to be. As if holiness is something we are to accomplish before we have peace with Him. But that matter was taken care of by Christ on the Cross. We have peace, period. We can now live in relationship with God, and it is from that relationship we find the ability to live as He designed, to obey Him from the heart instead of obligation as they did under the Old Testament Law.
We still live in a fallen world, though, bound by a fallen nature. Living as He designed goes contrary to our nature. We have been grafted in—we’re not a part of the trunk that gave us root. It feels more natural to live without Him.
It is within this context that Paul is writing in Roman’s twelve.