All too often see seek to find out whether or not we *can* speak, whether or not we *can* admonish. Can I rightly complain about what that person over there has done. Is it "public" enough for me to complain about it publicly? Can I unload on *him* because he is teaching false doctrine. Can I speak, and still maintain a clean conscience?
That isn't the question we should be asking. We should consider this: "Must I speak?" That's the standard Paul sets in 1 Corinthians 9 - "For if I preach the gospel, that gives me no ground for boasting. For necessity is laid upon me. Woe to me if I do not preach the gospel!" Am I compelled by God and my office to speak.
I am compelled to preach Christ and Him Crucified.
I am compelled to warn my flock and family of false doctrine.
I am also compelled by Christ to love my neighbor, to pray for my enemies, even the ones who persecute me. I am compelled to strive to restore the erring in a spirit of gentleness.
These are all things I *must* do. Can has nothing to do with it.
So, when you are going to speak, consider this. Is it merely something you have found a "reason" that says that you can - or is it something you must, something that you have to speak upon.
The latter is the way of kindness and gentleness and love. The former will let you cover-up and justify all sorts of sin.