The Bible generally discourages marriage between close relatives. In the Old Testament, God gave clear laws to the Israelites warning against sexual relationships among close family members such as parents, siblings, and close blood relatives. These instructions were meant to preserve moral purity, family order, and respect within the home.
Beyond the spiritual reason, such unions were also discouraged to protect families from complications and harm that could arise from such relationships. The Bible presents marriage as a union that should honor God and promote healthy, respectful relationships, not create confusion or disorder within the family structure.