A Few Questions

Life gets really dirty and hard sometimes.

I have a friend who is in some serious trouble. This person is headed down an extremely dangerous road with some pretty major, painful consequences and I don't really know how to help. There is an addictive, possibly neural chemical element to it all that I don't know how to deal with.

Knowing my own sins and shortcomings I can sympathize with this person but even so, I can't fully wrap my head around the situation. I wish I could just smack him/her straight.

What is the best Christian response I can offer my friend and his/her spouse?

What do you do when someone you love is caught in a vicious cycle of sin/ repentance/ re-offense/ and regret?