Moses writes this about the righteousness that is by the law: “The person who does these things will live by them.” But the righteousness that is by faith says: “Do not say in your heart, ‘Who will ascend into heaven?’” (that is, to bring Christ down) “or ‘Who will descend into the deep?’” (that is, to bring Christ up from the dead). Romans 10:5-7
Even in the Christian faith today there is a “tension” between faith and the law, though it is somewhat different than Paul writes about. The law today refers to rules that Christians make for their own lives. Drinking alcohol, smoking, and working on Sundays are rules that Christians have made for themselves in the recent past. You don’t have to think hard to come up with a half dozen others.
The righteousness by faith, however, says like St. Augustine, “Love God and do what you want.” The general idea behind the statement is that if you are loving God you know what pleases Him. The corollary is also true then: when you cease to love Him, it’s probably not wise to do what you want.
There will always be Christians who come down on one side of the “argument” or the other. On the one hand, it’s very easy to get wrapped up in the rules because they provide neat boundaries. On the other hand, there is freedom in Christ.
Sometimes, though, we can come down right in the middle so as not to offend a weaker brother by our actions. It’s a healthy tension to have in our lives.