He is called "Damascene" on account of being associated with Damascus, the capital of Syria.
He defended the practice of the veneration of images against the Iconoclast heresy.
He is called the "Golden Speaker" for his great eloquence and is a great poet of the Eastern Church.
He was born into a financially well-off family. His father was a public minister in Damascus, but John renounced this life, dividing his possessions among the poor and entered the monastery of St. Sabas, near Jerusalem. He dedicated himself to his studies and to writing. He wanted to make the rich treasures of the faith known to the whole world.
When Leo of Isauric, the emperor of Constantinople, prohibited the veneration of sacred images and echoing the iconoclasts who accused Catholics of adoring images, St. John Damascene became the spokesperson for the orthodox teaching of Catholic doctrine. We do not adore images, but we venerate them.
"What a book is to those who can read, that an image is to those who cannot read. The image speaks to the sight as words to the ear; it brings us understanding. Images are the catechism of those who do not read." - St. John Damascene