The Bible mentions bestiality in four different passages. Exodus 22:19 says, “Anyone who has sexual relations with an animal must be put to death.” Leviticus 18:23 declares, “Do not have sexual relations with an animal and defile yourself with it. A woman must not present herself to an animal to have sexual relations with it; that is a perversion.” Leviticus 20:15-16 commands, “If a man has sexual relations with an animal, he must be put to death, and you must kill the animal. If a woman approaches an animal to have sexual relations with it, kill both the woman and the animal. They must be put to death; their blood will be on their own heads.” Deuteronomy 27:21 agrees, “Cursed is the man who has sexual relations with any animal.” From these verses, it is abundantly clear that, according to the Bible, bestiality is a horrible, unnatural, and abominable sin.
Why is bestiality condemned so strongly? First, it is an unnatural perversion. Clearly, human beings were designed/intended to mate with other human beings, not animals. In the creation account, none of the animals were “suitable” for Adam (Genesis 2:20). Second, bestiality represents the ultimate of sexual deviancy. The fact that the animal was to be put to death (Leviticus 20:15-16), despite the fact that it would be “innocent,” indicates how wickedly perverse bestiality is. Third, and perhaps most importantly, bestiality essentially denies the uniqueness of humanity which God created in His image (Genesis 1:27). Bestiality lowers humanity to nothing more than an animal, a beast which is unable to distinguish right from wrong, natural from unnatural, love from lust.
The New Testament nowhere mentions bestiality, but that should not be interpreted as an allowance for bestiality or a weakening of how strongly God condemns bestiality. While the Old Testament Law was fulfilled with the death and resurrection of Jesus Christ (Romans 10:4;Galatians 3:23-25;Ephesians 2:15), the Law, in most instances, is still a guidepost for what is right or wrong, moral or immoral. Unlike some of the other Old Testament commands, there is nothing in the context of the biblical condemnations of bestiality that in any way limits the applicability to Israel as a nation or to any particular time period. While the death-penalty aspect of the command does not need to be enforced, the fact that bestiality is still a horrible, disgusting, perverted, and abominable sin is abundantly clear.