If married priests cannot advance in the Church (become bishops, etc.) than can un-married priests doso?
There are two ways a married priest can become a bishop: when his wife passes away, or if she voluntarily joins a monastery.
"O Cross of Christ, all-holy, thrice-blessed, and life-giving, instrument of the mystical rites of Zion, the holy Altar for the service of our Great Archpriest, the blessing - the weapon - the strength of priests, our pride, our consolation, the light in our hearts, our mind, and our steps"
Met. Meletios of Nikopolis & Preveza, from his ordination.