Clerical Celibacy
The Catholic Church demands celibacy--no voluntary sexual
pleasure, hence, no marriage--as a prerequisite to the order
of presbyter and bishop.
The primary basis for the requirement of celibacy is clearly
the lifestyle example of Jesus himself.
The Church notes that the practice is sanctioned by the New
Testament.
Matthew 19:12
Some are incapable of marriage because they were
born so; some, because they were made so by others;
some, because they have renounced marriage for the
sake of the kingdom of heaven. Whoever can accept
 this ought to accept it.