What you can do for him is, most importantly, continue to pray for him. But also, join an Al-Anon group. Learn about yourself. You may be totally unaware of the ways in which you have become co-dependent through the years of relationship with an addict. Learn to recognize how you have unintentionally enabled his addiction - not in guilt or judging yourself. It isn’t your fault, but it is your reality whether you know that yet or not. My addict son lives with my sister - she doesn’t even realize she enables his addiction, and she can’t understand why SHE needs help when he’s the one with the problem. And so the co-dependent relationship continues, they’re both trapped in it, and he is never motivated to make a change. She makes his addiction (his escape) too comfortable for him. If the critical people in relationship with your Dad can become aware of their role in this reality, and learn to make changes, it will be the best thing any of you can do to help him stay sober.