Paul in his letter to the Romans writes in 6:12-13:
Therefore do not let sin reign in your mortal body so that you obey its evil desires. Do not offer any part of yourself to sin as an instrument of wickedness, but rather offer yourselves to God as those who have been brought from death to life; and offer every part of yourself to him as an instrument of righteousness. For sin shall no longer be your master, because you are not under the law, but under grace.
Clearly the two "do not" phrases are commands - "Do not let sin reign" and "Do not offer". Less clear to me, though, is the phrase, "For sin shall no longer be your master". Is that phrase simply a re-statement of the previous two commands? Or is it possibly a grounding for the two commands? The NET translates it "For sin will have no mastery over you", which suggests it is not an imperative; but is that a fair translation?
Is the phrase an imperative or is it an indicative?