Strange question to ask on this site. Most of us wouldn't trust a cleric of any variety. And 'sin' only has meaning within the context of religion

Who says we trust clergy? From my perspective they peddle bullshit and extort people for a living. No way I'd trust someone doing that.

It's so widespread because people suck. Especially people who peddle bullshit and extort people for a living, and aren't supposed to have sex. Forced celibacy, now there's an inhuman concept if I've ever seen one.

Clergy = low IQ, power hungry, useless pedophiles.

Sin is a religious construct. All humans are capable of wrongdoing, being religious or having a belief in god doesn’t alter that. I believe though, that people who have certain proclivities, such as those who are drawn to paedophilia, find entering the clergy an easy way to access children. This applies to all religions, the C of E, R.C., and all the others. The fact that people believe that they are more honest and trustworthy because they are ordained by god, makes it all the easier for them to gain trust and therefore all the more reprehensible when they betray that trust.