It is our position that polygamy cannot be equated with adultery because the bible does not define it as such, but simply treats it as a form of marriage.

We tackle adultery first, because most times this is the first accusation against Biblical Plural Marriage. Modern Churchianity considers having a relationship with more than one partner as adulterous. They have a different definition of adultery than the bible does, and so we begin with a biblical definition of adultery.

We find three verses in Mosaic Law that deal directly with adultery, and they are listed below. Strong’s numbering system is retained for the sake of clarity.

Exo 20:14 Thou shalt not3808 commit adultery.5003

Lev 20:10 And the man376 that834 committeth adultery5003 with854 another man's376 wife,802 even he that834 committeth adultery5003 with854 his neighbor's7453 wife,802 the adulterer5003 and the adulteress5003 shall surely be put to death.4191, 4191

Deu 5:18 Neither3808 shalt thou commit adultery.5003

The Hebrew word is H5003 in Strong’s Concordance. Please note that, in Scripture, the definition of adultery is based upon the woman’s marital status, and not that of the man’s. Even in Lev 20:10, the man is referred to as an adulterer, with the same Hebrew word used, for he causes her to break wedlock. This theme occurs later in the NT, which we will soon address.

naw-af'
A primitive root; to commit adultery; figuratively to apostatize: - adulterer (-ess), commit (-ing) adultery, woman that breaketh wedlock.

Read on here:

The Biblical Concept Of Adultery Part 2

The Biblical Concept Of Adultery Part 3