I was that hostile and rebellious teenager. I am happily married now to my wife of 15 years with 2 children. My life is on track and things are going well. First, never give up hope on them.
Second, try to find out, lovingly and patiently, what is bothering them. Something must have happened (though not always) to bring this attitude and approach to life on. Give them all the time they need to tell you (Months if necessary). Finally, love them as they are. Don't push them to change. Love them without conditions. It will be difficult, but anger, judgment, and pushing them will not do. Never lose hope. Always love.