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

            There are many reasons for divorce, some necessary and most others not necessary due to the consequences of a sinful, selfish heart.  If a person leaves a marriage unbiblically then marries another person, it’s like they are committing adultery.  In God’s eyes, they are stilled married.  That’s especially true if the person commits adultery to find “happiness” in another relationship.

            Jesus gave this example in such a way that it appears the person divorces to remarry.  Jesus clearly calls that adultery.  If the person divorces (for biblical reasons) then later meets someone and remarries, it doesn’t appear that’s adultery.