By St. Nikolai Velimirovich
There are three types of praiseworthy zeal: zeal in cleansing oneself of sinful desires and thoughts, zeal for the truth of the Faith, and zeal for God's justice among men. All three of these filled the soul of St. Nicholas the Wonderworker to perfection.
He showed zeal in purifying himself throughout his life, vigilantly guarding over his heart. He especially showed zeal for the truth of the Faith at the First Ecumenical Council in Nicaea  when he entered into a fearful confrontation with Arius. His zeal for God's justice among men was seen particularly in two notable events, when on each occasion he saved three innocent men from the punishment of death.
Once, in his absence from the city of Myra, the avaricious commander Eustathius condemned three men to be beheaded, receiving a bribe for this from some of their enemies. Informed of this, St. Nicholas returned to Myra with the greatest haste. The condemned men had already been brought to the place of execution, and the executioner had already raised the sword over the innocent men. At that moment, Nicholas grabbed the sword, pulled it out of the executioner's hand, and freed the condemned men. Afterward, he rebuked the commander Eustathius and brought him to shame and repentance.
In a similar way, three imperial commanders - Nepotian, Ursus and Herpylion - were slandered before Eulavius the Eparch of Constantinople and before the emperor himself. The emperor signed their death sentence. On the eve of their execution, the three commanders prayed to God, saying: "O God of Nicholas, deliver us innocent ones from death!" That night, St. Nicholas appeared to both the emperor and the eparch in a dream, rebuked them for this injustice, and ordered them to free the three commanders from prison immediately. The next day, the emperor and eparch each related to the other the same dream and they immediately freed the commanders, both from the death sentence and from prison.