[QUOTE=Numenor King]P.S. (This is not a bash on catholics.) It is an honest question, why do they teach celibacy for priests when Peter himself was married and many of the Apostles? This is something I have always wondered. (I know Celibacy is a calling for some people such as Paul, and Jesus of course, but in the Bible I also see that many of the leaders were married.)[/QUOTE]
Priests are to remain celibate to avoid divided obligations -- one to God, and the other to the spouse.
If priests remain celibate, it is believed that they can more fully perform their ministry. In other words, they can devote their fullest efforts to God and the Church, instead of having to devote their fullest to both God (as required by Holy Orders) and spouse (as required by Matrimony). More than likely, this would be exponentially more difficult, if not impossible. And then it would get even more complicated when children come into the picture.
Converted priests, and some other instances, however, can be exempt of this practice.
May the mass times acceleration be with you.