As the wife of an addict, you have to decide at some point if you can ever trust this man. Trust is the basis of all relationships, including that with your children, and your children with him as a father. If he lies, there cannot be that bond there. If he cannot understand that, I would say there will never be any progress. I am of the camp that it takes someone who lies like that intensive treatment to stop b/c that is how they get through life.
So sorry you are going through this.