Is marriage between cousins a sin?
Introduction. Under the Law of Moses, there were several references prohibiting sexual relations with a close relative (Lev. 18:6-18; Lev. 20:11-21; Deut. 27:20-23). However, the New Testament (which is binding on Christians today) does not contain any specific teaching on the subject (incest). Only the general term "fornication" is used, referring to all forms of immoral sexual activity. This includes sex between two or more unmarried persons, adultery, homosexuality, incest, and bestiality (Acts 21:25; 1 Cor. 6:9; Heb. 13:4). I would conclude that whether a given relationship between distant relatives would be sinful or not depends on the laws of the land that usually regulate such marriages (Rom. 13:1-7).
Other considerations. Although civil law may permit marriages between close relatives (e.g., first or second cousins), one real problem of such marriages is the danger of genetic problems with the children. This danger is probably one reason the prohibition was issued in Leviticus 18. If a couple was contemplating such a marriage, I would think they would want to determine in more detail the medical findings relative to genetic dangers of cousins, especially first cousins, producing children.
Other considerations. Although civil law may permit marriages between close relatives (e.g., first or second cousins), one real problem of such marriages is the danger of genetic problems with the children. This danger is probably one reason the prohibition was issued in Leviticus 18. If a couple was contemplating such a marriage, I would think they would want to determine in more detail the medical findings relative to genetic dangers of cousins, especially first cousins, producing children.