While the wicked Emperor Valens was in Nicaea, prominent Arians approached him requesting that he drive the Orthodox from the cathedral and give it to them. The ruler, himself a heretic, forcibly removed the faithful and allowed the dissenters to occupy the building, after which he left for the Imperial City. The entire community of the Orthodox, which was of considerable size, was griefstricken. While matters were in this state, the great helper and protector of all the churches, Saint Basil, arrived in Nicaea. Weeping and lamenting, the flock of true believers informed him of what the Emperor had done. The blessed one comforted them and hurried to Constantinople, where he presented himself to Valens and said, “It is written, ‘The King’s honour loveth judgment’, and Wisdom tells us that ‘the King’s judgment is righteous’. Why, then, 0 Emperor, have you pronounced an unjust sentence, expelling the Orthodox from their holy church and giving it to misbelievers?”
The Emperor replied, “Have you come to insult me, Basil? It does not behoove you to speak thus.”
“It would certainly behoove me to die for the truth,” retorted Basil.
The chief cook of the palace, whose name was Demosthenes, was standing nearby, and wishing to abet the Arian cause, interjected and crudely reviled the saint. “Behold,” laughed Basil, “a new Demosthenes, this one an illiterate!” The humiliated cook muttered something, to which the blessed one responded, “Your business is pots and pans, not the dogmas of the Church.”
Furious with Basil, but knowing that he had acted wrongly, the Emperor commanded, “Return to Nicaea and judge between the factions, but do not show favoritism to your party.”
“If I judge wrongly, send me to prison, expel my co-believers, and give the church to the Arians,” said the man of God.
Basil went back to Nicaea with an imperial decree, assembled the Arians, and announced, “The Emperor has given me authority to decide whether you or the Orthodox should have the church you took by force.”
The Arians replied, “Judge, then, but as the Emperor would.”
“Come, Arians and Orthodox,” exclaimed Basil; “we will lock the church! Both sides will affix their seals and set strong guards of men they trust. Then pray for three days and nights, you Arians, and return. If you can open the doors by your supplications, the church will be yours in perpetuity. If you cannot, we shall pray for a single night and go to the church, chanting a Litia. We shall have permanent control of the building if the doors open for us; otherwise, it will be yours again.”
This proposal pleased the Arians, but the Orthodox were vexed with the saint, protesting that he gave the heretics an unfair advantage out of fear of the Emperor. Nevertheless, both sides agreed, locked the church, sealed it, and set guards. The Arians prayed for three days and nights, but their prayers achieved nothing; so they continued to entreat God’s mercy until noon of the fourth day, crying, “Lord have mercy!” When the doors failed to open, they dispersed, hanging their heads in shame. Meanwhile, the great Basil assembled the Orthodox men, women, and children, and led them to the Church of the Holy Martyr Diomedes, outside the city. He celebrated an All-Night Vigil there, then proceeded with the crowd to the cathedral, chanting, “Holy God, Holy Mighty, Holy Immortal, have mercy on us.” Halting before the portals, he commanded the people, “Raise your hands to heaven and cry with heartfelt ardor, ‘Lord have mercy!’” After they had prayed, the saint ordered that there be silence. He made the sign of the Cross over the doors thrice and shouted, “Blessed is the God of the Christians, always, now and ever, and unto the ages of ages.” The people answered, “Amen.” Suddenly the earth quaked, the locks broke apart, the bars fell to the floor, the seals split, and the doors flew open, slamming against the wall as though a mighty wind were blowing or a fierce tempest raging. Chanting, “Lift up your gates, 0 ye princes; and be lifted up, ye everlasting gates, and the King of Glory shall enter”, Basil hurried into the building with the whole congregation of the Orthodox. After celebrating the divine service, he joyfully dismissed the faithful. Many Arians (who had returned in great numbers to see how matters would end) renounced impiety and joined themselves to the true believers. When the Emperor learned of Basil’s judicious handling of affairs and the glorious miracle, he marveled greatly and denounced vile Arianism; nevertheless, blinded by malice, he did not turn to Orthodoxy. Later, he perished miserably. Defeated and wounded in a battle in Thrace, he fled and cowered in a barn full of straw. His pursuers surrounded the building and set it on fire. The Emperor was burned alive, and his soul departed to everlasting flames. The tyrant’s demise took place after the death of our holy father Basil, but in the same year.
source: mystagogy