Priests are only natural human beings. Why are they forbidden to marry?

The Catholic Answers

Because they do not wish to be only natural. They wish to be supernatural. St. Paul was human, but he did not marry. And like St. Paul, Catholic Priests wish to centre their interests in Christ and share their hearts with no one else. Meantime, they are not forbidden to marry as human beings. They are forbidden as Priests. Prior to their choice of the Priesthood, every Priest could have chosen marriage instead had he wished.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty