Richard Lusk writes:
The pure grace of the gospel is not threatened by a call to obedience. Indeed, the gospel, properly preached, understood, and embraced, demands and promises obedience, In the Scriptures, heralds of the gospel essentially interchange faith and repentance as appropriate responses to the message (cf. Acts 2:38; 16:34). In other place, Scripture speaks of “the obedience of faith” and calls hearers to “obey the gospel” (Romans 1:5; 2 Thessalonians 1:8). In still other texts, faith and obedience (cf. Romans 10:16) as well unbelief and disobedience (Hebrews 3:18-19) are interchangeable. The basic gospel confession is, “Jesus is Lord” (Romans 9; 1 Corinthians 12:3) – which is to say, “He has given himself for me, and I now owe him my allegiance.” In the gospel, we find that God’s righteous requirements are not legalistic imposition, but gracious gifts he promises to work in us (cf. Romans 8:1-4).
The only kind of faith that justifies is a faith that lives – that is to say, a faith that loves, obeys, repents, calls, and seeks. Thus, faith can be seen (cf. Mark 2:5) and demonstrated (James 2:18); it is embodied and embedded in outward action. True, at the moment of initial justification, faith has not yet done good works. But the kind of faith that lays hold of Christ for justification is a faith that will issue forth in obedience, not because something will be added to that faith a nanosecond after its conception (as if faith had to be “formed” by additional virtues, ala Roman Catholic teaching), but because that faith already carries within itself the seeds of every virtue.
Found in A Faith That is Never Alone, “From Birmingham with Love: ‘Federal Vision’ Postcards” p. 121-2