We Christians are priests. Among us Chrsitains who are Priests are Ordained Priests. As you well know, the Old Testament Priests served in the Temple once a year, during which time they offered the Sacrifice. During the time they offered the Sacrifice they had to be continent. Continence meant they had to abstain from conjual relations.
The New Testament Priethood of the ordained offer the Sacrifice Daily. Ergo, perpetual continence/chastity in imitation of Jesus