A priest is a special exalted person with a direct line to God, or the Gods and Goddesses, if you're an ordinary believer you you don't have that exalted line. So if you want help or favours from any divinity you ask a priest to contact the divine whatever on your behalf. Some religions have priestesses as well as priests.
Afterwards you mustn't forget to pay the priest or to put money into the collection box.
Roman Catholic priests
—Matthew 19:12 [1]
| “ | For there are some eunuchs, which were so born from their mother's womb: and there are some eunuchs, which were made eunuchs of men: and there be eunuchs, which have made themselves eunuchs for the kingdom of heaven's sake. He that is able to receive it, let him receive it. | ” |
Roman Catholic priests take vows of celibacy, and are not allowed to marry. In spite of this, they are supposed to be the primary source of counsel and advice for troubled married couples and families in general. A minority of RC priests abuse children.
There is a good and a a bad side to Christianity, see the category page
References
Adapted from an old RationalWiki article