He was born to an eminent family in Cyprus, and was well-educated. He was married and had children, but when his wife died he left his family to live as a monk in Syria. There he became known and loved for his learning, humility and kindness to all, and the people of Apamea chose him as their bishop. As bishop, he worked with evangelical fervor to bring the mostly-pagan people to Christ. When a pagan temple was burned down, some pagans blamed Marcellus, seized him, and threw him into the fire, where he perished.