Christians or anyone else do not have to suffer in silence when being physically abused.
In the USA, in the UK, in all free countries actually the legal systems provide domestic remedies for families/ individuals to protect themselves against dangerous persons. In the USA specifically, states' laws provide a means in which victims of domestic abuse/ assault can apply to their local court and request a protection order. A protection order would be used where a family/ individual wants to stop all contact with the offender. It's not a criminal law remedy it's a civil remedy although the matters may be criminal in nature too.
Here is a relevant website which tells you how to go about it.
How to Get a Protective Order In the United States: 8 Steps
There are two ways to get a protection order, the first is via for paying for a lawyer or through legal aid systems. The other, if you feel you can and will have some support at court from a family member or friend, is to make a motion to the judge and request a hearing for a protection order. You however will require some evidence perhaps from the crime itself such as documentation from the police station, in the form of medical statement from doctors or photographs of bruising/ other harm. The court will take into account witness statements too.
Do not suffer in silence, you guys live in free countries with legal systems which will support you.
Tom, just a friend/ a helper (not a qualified lawyer...but has legal knowledge through formal legal studies).