There is no biblical basis for priests and nuns to be celibate. Although some may claim there exists such a passage, it simply isn't there. That is not to say celibacy of a sort was unheard of - in fact, it certainly did exist in many cultures - but never in quite the foreboding way it exists in the Catholic Priesthood today, and certainly not within the Jewish communities Christianity sprang from (not in the same fashion, anyway).

From my discoveries, the practice of celibacy from the doctrine of the early Church was mostly based on fear. Specifically of the female side of god that was venerated, even during the formation of Christianity. Along with the surpression of any idea of women doing anything but serving men - when there were, in fact, female priests - was the surpression of the Virgin Mary Goddesss Cult, Priestesess of Isis, etc. Celibacy rose out of fear that long-standing customs involving Goddesses would continue, thus threatening this burgeoning Church's new regime. All avatars of Isis, Lilith, and the Shekhina - all symbols of power and motherhood - had to be erased from the popular mind. And so they were, though of course, not completely.

To allow the possibility of, not a female servant, but female counterpart was very scary to those who were riding the "One (Male) God, One Bishop" train. Their foundation of this new Christianity - founded on the ideology of of Paul (a deified Jesus) and the mental and physical descendants of Peter (Often termed "The First Apostle" by the Catholics, upon his bloodline was the Church founded) - was built upon Jesus covering all of the bases that were normally taken over by other counterpart or related dieties.

It is true at this point the Jewish God was as well an all-in-one diety, but that was not always so. Yahweh, or more accurately, YHWH, represented four different kingdoms: the Father, The Mother; The Son, The Daughter. I add this for perspective, as Judaism and Christianity, regardless of how you look at it, are hopelessly entertwined; and if Jesus is to be retroactively applied as the creator God, then one must acknowledge his roots.

It is these past things that the early Church feared, and thus sought out to eliminate every remnant of their existence. One of the main steps was to seperate the sexual and the spiritual - which were connected at the time in various fashions - into very seperate and disjointed categories. So much so that the sexual became evil and untouchable....and down that bloodline of thought, a product of the elusive Satan; as apparently are homosexuals and condoms, according to our recently passed Pope John Paul II.

It is in this tradition that Catholic Priests are celibate. Catholic, perhaps ironically, perhaps not, means universal - and where the universe would be without sexual acts, well...I don't know. Perhaps cleaner?