13 Do not angle for compliments, lest, while you win the popular applause, you do despite to God. “If I yet pleased men,” says the apostle, “I should not be the servant of Christ.” He ceased to please men when he became Christ's servant. Christ's soldier marches on through good report and evil report, the one on the right hand and the other on the left. No praise elates him, no reproaches crush him. He is not puffed up by riches, nor does he shrink into himself because of poverty.
Joy and sorrow he alike despises. The sun does not burn him by day nor the moon by night. Do not pray at the corners of the streets, lest the applause of men interrupt the straight course of your prayers. Do not broaden your fringes and for show wear phylacteries, or, despite of conscience, wrap yourself in the self-seeking of the Pharisee. Would you know what mode of apparel the Lord requires? Have prudence, justice, temperance, fortitude. Let these be the four quarters of your horizon, let them be a four-horse team to bear you, Christ's charioteer, at full speed to your goal.
No necklace can be more precious than these; no gems can form a brighter galaxy. By them you are decorated, you are girt about, you are protected on every side. They are your defence as well as your glory; for every gem is turned into a shield.
Source: Letters (New Advent)