You know, I'm a tough cookie about enableing and co-dependance, but I think that every now and then a helping hand and someone who unconditionally cares, makes a difference in someone's life. And why would a addict be ruled out as being one of those someones? Despite all I have been though with my addicts, and all the praying I have done that seems to no avail at times, I still believe that through God all things are possible and He uses people like you and your husband as instruments.
I just advise you to be careful to keep a boundary not to enable and be alert for manipulation.. But, obviously, you are doing some things right with this young man to posture him for success... Even if it is temporary, any amount of time clean and on the the right track is an investment in recovery.
I would like to send my son over to you. Got any openings? Maybe you should start a sober living house. Seems like you guys have a gift.