So throwing him in jail solves the problem? He's a fundamental Christian upset at taking the Lord's name in vain (one of the ten commandment, I believe). How can you defend a person who verbally attacks the religious beliefs of another in his own home?
Are you suggesting he was justified to hit his wife?
It's easy to defend her. It's against the law to assault another person including your wife. It's not against the law to take the Lord's name in vain. Instead we have something called freedom of speech.
Exceptions are made for corporal punishment of children, but even then there are limits and grey areas where you can be accused of child abuse.
Taking the Lord's name in vain is not an attack on anyone's religious belief. It IS a stupid thing to do. When the Creator of the universe tells you not to take his name in vain, and you do it anyway, it's just not the wisest thing you can do.
And while it can cause offense, in that if you love the Lord, you don't want to hear people disrespect Him. Words should never result in physical assault. If the words are libel or harassment there are criminal and civil legal processes that can be employed.
If it's done by your spouse, it's your fault, because you married her. The best you can do is gently reprimand and encourage and model proper behavior.
Arguing that he is justified in assaulting her because he was offended is the same flawed logic that Muslims use to kill Christians and even their own children.
This is how you send people screaming to the opposition. We can't afford to make mortal enemies of our family members any longer. Get a grip and tape your hands to your hind end if you have to...
You are a piece of work.
And that work is in the septic tank.