Jesus says pretty clearly in Matthew 5:31-32 that adultery is the only grounds for divorce (at least for Christians). But it should really only apply if the spouse that commits adultery is unrepentant. If the offending spouse is truly broken and seeks forgiveness, it should be given, painful as it may be. Even so, clearly some people are called to stay with a spouse who commits adultery even if they are unrepentant and continue doing it (see Hosea).

As for abuse, I think it's important that the wife leave that situation and report her husband to the police. She shouldn't necessarily divorce him, but she shouldn't stay in a harmful environment either. If it is clear he is repentant and the abuse stops, then I believe she is obligated to return to him.

__________________
Mason
Member, Redeemer Presbyterian Church (PCA)
New York, NY

"Come now, and let us reason together," says the Lord, "Though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall be as wool." - Isaiah 1:18