Authors:

The world was won for Christ not by arguments but by sanctity: "What you are speaks so loud, I can hardly hear what you say."

Peter Kreeft, Fr. Ronald Tacelli (2016). “Handbook of Catholic Apologetics: Reasoned Answers to Questions of Faith”, p.19, Ignatius Press
The world was won for Christ not by arguments but by sanctity: What you are speaks so loud, I can hardly hear what you say.