What does the bible say about infidelity? I have not been married yet and am just now learning the Lord's word but we have been common law married for 4 years now. I want to forgive and try to work on this but does the Bible say I should even though we have not gone to the church for the wedding?
In general, common law marriage only applies (in the United States) if both parties agreed to be married, lived as husband and wife (male and female only), and publicly represented themselves as being married, and lived in one of the following states/districts:
District of Columbia
Georgia (if created before 1/97)
Idaho (if created before 1/96)
New Hampshire (for inheritance purposes only)
Ohio (if created before 10/91)
Pennsylvania (if created before 9/03)
If all these things apply to you, then your common law marriage is probably valid by civil law, and therefore valid biblically, whether or not a formal ceremony was performed. (In Texas it is called “informal marriage.”) If you have been thus married, any sexual infidelity is definitely what the Bible calls adultery.
While the Bible may allow divorce in cases of adultery (Matthew 5:32; Matthew 19:3-12; see my answer about divorce at What Does the Bible Say About..Divorce?), it does not say you have to get divorced. The spouse that was cheated on may choose to forgive and carry on with the marriage. In fact, this would probably be preferable if it was a one-time thing. We are encouraged to forgive (see Matthew 18:21-35). If, after having been forgiven, the unfaithful spouse continues in the practice of adultery, the other spouse may decide that he (often it is the man) is not going to change, and choose to divorce him. The Bible, however, puts no such conditions in the case of infidelity.