First, let me put the scale of this scandal in perspective with some personal statistics. I personally know of two sex scandals involving married Protestant ministers. One was a consenting adulterous relationship, and the other involved a number of young girls. I do not have any personal knowledge of any sex scandals involving Catholic priests, and I know around four times as many Catholic priests as I do Protestant ministers.
I should clarify that that the scandal involving a number of young girls was in a congregation that denies being Protestant (although an examination of their history proves that they are). They will also deny that the man involved in the scandal had any authority in their church because he was only a professional preacher, not a deacon or an elder. This, of course, is a ruse because he was the main teacher of this congregation.
The scandal in this congregation also mirrors the Catholic scandal of bishops putting supposed rehabilitated sex offending priests in positions where they could re-offend because the elders of this congregation were aware of at least one sexual offence when this man was in Bible college. There were no legal charges laid in this earlier offence, and so the whole affair was kept quite. However, knowing of this past offence, the elders allowed this man to be in a position where he was alone with young girls.
The purpose of these last three paragraphs is simply to point out that this is not just a problem in the Catholic Church. The reason the Catholic problem is so publicised is because the secular media has a bias against the Catholic Church. Statistically speaking, sexual offences among Catholic clergy is lower than in the general public. As well, more than half of the offenders in sex abuse cases are married, divorced or in a common-law relationship.
Marriage does not stop a potential sex offender from offending. Even if he does not do anything illegal, he will still offend in his mind, which Christ affirms is just as sinful:
"You have heard that it was said, 'You shall not commit adultery.' But I say to you that every one who looks at a woman lustfully has already committed adultery with her in his heart." (Matthew 5:27-28)
In his General Audience of October 8, 1980, Pope John Paul the Great points out that Christ does not say "one who looks at a woman that is not his wife lustfully," but "one who looks at a woman lustfully." Thus, Christ implies that even if a man looks at his own wife lustfully, he commits adultery "in his heart" (I use the pope's actual quote in my next Weekly Thought).
Purity of heart is just as important in marriage as it is in celibacy. A man that habitually looks at women, or men, lustfully and can't stop himself from doing so is not only unfit for the priesthood, he is unfit for marriage. He may never act out on these thoughts, but the fact that he can't stop himself from thinking these thoughts means he has a deep rooted disorder that must be corrected before he can make a vow of celibacy or make a vow of marriage.
Marriage makes some sexual acts seem moral in the eyes of other Christians; however, if such acts are motivated by lust and not love, they are in fact immoral no matter how they may appear. In time, such acts will likely no longer satisfy, and acts that are blatantly immoral will be sought. So as to keep up appearances, these blatantly immoral acts will be done in secret, but as a person becomes more and more sexually disordered, he will take greater and greater risks in losing his reputation as a good Christian.
If a person with disordered sexual desires gets married, there is always the potential that the children resulting from this marriage will become the object of these disordered desires. Marriage puts a person with disordered sexual desires in a legal situation where he is alone with young children.
Even if a man is able to quench all his lust with his wife, there is no guarantee that she will always be sexually available to him. A medical condition may arise, such as a coma, where she cannot have sexual relations with him for months or even decades. How can he quench his lust if something like this happens? He will most likely look for a sexual outlet beyond that of his marriage.
In such a scenario, the only moral thing for a man to do is to remain faithful to his wife, which would require remaining celibate, possibly for the rest of his life. Such a heroic life could be forced upon any married man; however, some men freely choose such a life, many of whom become Roman Catholic priests.
A married priesthood would not have stopped the clergy sex abuse scandal in the Roman Catholic Church. All a married priesthood would do is bring more women and children into the scandal. As I mentioned above, more then half of sexual offenders have, or had, a legitimate or semi-legitimate sexual relationship. Such a relationship does not stop one from committing a sex crime.
Of course, a good percentage of priests involved in the clergy sex abuse scandal would still have chosen celibacy even if a married priesthood was an option for them. They chose the vow of celibacy as a legal way of suppressing their disordered sexual desires. Only mandatory marriage would have stopped them from becoming priests.
Mandatory celibacy did not cause the clergy sex abuse scandal in the Roman Catholic Church. What caused the scandal was admitting men to the priesthood that were not only unfit for the priesthood, but also unfit for marriage.