With tact and not temper…

In order to avoid discord, never contradict anyone except in case of sin or some danger to a neighbor; and when necessary to contradict others, do it with tact and not with temper.
— Saint Louis IX (1214-1270)

Gladly accept reproof…

Just as sailors, in the hope of gain, gladly endure the burning heat of the sun, so those who hate wickedness gladly accept reproof. For the former contend with the winds, the latter with passions.
–Saint Mark the Ascetic (Fifth Century)

Reproving will not help the proud…

When someone boasts about his virtues, do not try to help him by reproving him. For a man cannot love showing off and at the same time love the truth.
–Saint Mark the Ascetic (Fifth Century)