Dominican priest Father Vincent McNabb said that one sign of real intelligence is the ability to recognise holiness.
Sanctity tends to hide itself. It often takes a discerning eye to see the working of God's spirit in a person's life. More than once in the Gospels Jesus asks the leaders of the people to look beyond his words to the witness of his life.
When Jesus was asked, "If you are the Messiah, tell us plainly," he answered, "I have told you, and you do not believe. The works that I do in my Father's name testify to me." (John 10: 24-25)
When John the Baptist's followers pressed the same question, Jesus replied: "Go back and tell John what you see and hear." (Matthew 11:4)
Jesus pushes me and you to look at own lives. What we say about our faith matters little compared with the presence or absence of truth and justice and love in our daily living.