Amphilochios, Bishop of Iconium - O God of our Fathers, ever dealing with us according to Thy gentleness: take not Thy mercy from us, but by their entreaties guide our life in peace.

Reading from the Synaxarion:

Saint Amphilochius, who was born in Cappadocia, shone forth in
asceticism and divine knowledge even from his youth. He was consecrated
Bishop of Iconium in 341, he struggled courageously against the
blasphemies of Eunomius, Macedonius the enemy of the Holy Spirit, and the
followers of Arius. He was present at the Second Ecumenical Council of the
150 Fathers, which took place in Constantinople, convoked during the
reign of Theodosius the Great in the year 381. In 383 Amphilochius
wished to persuade the Emperor Theodosius to forbid the Arians from
gathering in Constantinople and to commit the churches to the Orthodox, but
the Emperor was reluctant to do such a thing. The next time that
Amphilochius entered the palace, he addressed Theodosius with proper honour,
but slighted his young son Arcadius in his presence. Theodosius was
indignant, and said the dishonour shown to his son was equally an insult to
himself. To this Saint Amphilochius answered that as he would not suffer
an insult to his son, so he ought to believe that God is wroth with
those who blaspheme His Only-begotten. Saint Theodosius understood and
admired Amphilochius' ingenious device, and he issued the desired edict
in September of the same year. Saint Amphilochius, having reached
deep old age, reposed in peace about the year 395. Saint Basil the
Great wrote many letters to Saint Amphilochius, his friend and Fellow
champion of the Faith, and at his request wrote his treatise On the
Holy Spirit, which besides demonstrating the divinity of the Holy
Spirit and His equality with the Father and the Son, defends the
Church's unwritten ancient traditions, such as making the sign of the
Cross, turning towards the East in prayer, no kneeling on Sunday, and so
forth.

Apolytikion in the Fourth Tone
O God of our Fathers, ever dealing with us according to Thy
gentleness: take not Thy mercy from us, but by their entreaties guide our
life in peace.

Kontakion in the Second Tone
O thunder divine, thou husbandman of faithful men, the Spirit's
clear trump, O axe that hewest heresies, Hierarch Amphilochius, thou
great servant of God the Trinity, ever with the Angels on high cease
not interceding for us all, O Saint.