What the Holy Bible says about Adultery:

27 “You have heard that it was said, ‘You shall not commit adultery.’ 28 But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart. (Matthew 5: 27-28)

19 For out of the heart come evil thoughts—murder, adultery, sexual immorality, theft, false testimony, slander. 20 These are what defile a person; but eating with unwashed hands does not defile them.” (Matthew 15: 19-20)

Jesus replied, “Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning. I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery.” (Matthew 19: 8-9)

11 He answered, “Anyone who divorces his wife and marries another woman commits adultery against her. 12 And if she divorces her husband and marries another man, she commits adultery.” (Mark 10: 11-12)

32 But I tell you that anyone who divorces his wife, except for sexual immorality, makes her the victim of adultery, and anyone who marries a divorced woman commits adultery. (Matthew 5: 32)

14 “You shall not commit adultery. (Exodus 20: 14)

17 “You shall not covet your neighbor’s house. You shall not covet your neighbor’s wife, or his male or female servant, his ox or donkey, or anything that belongs to your neighbor.” (Exodus 20: 17)

Marriage should be honored by all, and the marriage bed kept pure, for God will judge the adulterer and all the sexually immoral. (Hebrews 13: 4)