But the biggest is the prudential consideration. Will whatever say do ANY good whatsoever?
Yes, example is the #1 form of evangelization. St. Francis of Assisi said something along the lines of "Preach. Use words, if necessary."
If someone shows positive signs of being receptive to the faith, be "ready always to satisfy every one that asketh you a reason of that hope which is in you." (1 Pet. 3:15).
See: Treatise on Preaching
by Humbert of Romans, O.P. (d. 1277), a classic treatise on preaching/evangelization by a luminary of the Order of Preachers (Dominicans).