Catholic Doctrine   Fornication Fornication:  What is the teaching of the Holy Roman Catholic Church? The Catholic teaching of this matter is given to us by God Himself in the Bible:  "Take heed to keep thyself, my son, from all fornication: and besides thy wife never endure to know a crime."  (Tobias IV 13) "There shall be no whore among the daughters of Israel, nor whore-monger among the sons of Israel.                    (Deut. XXIII 17) "That you abstain from things sacrificed to idols and from blood and from things strangles and from fornicaton: from which things keeping yourselves, you shall do well. Fare ye well.   (Act. XV 29)