Mr. Warren would do best by simply telling the truth then. People are more apt to believe you whaen you act in truth as opposed to just talk about it.
From a purely tactical viewpoint, it's not always prudent for everyone to tell the truth. It can lead to all sorts of repercussions, including but not limited to the self-destruction of agendas that might otherwise have succeeded via the art of deception.
Cynical? You bet! But we're in the real world, and that's how certain folks operate in the real world -- and to blind ourselves to this reality is to refuse the call to be "wise as serpents and harmless as doves."
The end result of that kind of willful blindness is oft a reversal of those terms.