how successful can alcohol rehab be if someone does not believe in a higher power?

how successful can alcohol rehab be if someone does not believe in a higher power (God or anything)? It's one of the steps and my boyfriend is having trouble with that step but really wants to get better.... any suggestions???
the program he is in is telling him he has to believe in a higher power... please give me some feed back as to what I can do to help him get through this....

: http://alcoholdrugstreatment.info/how-successful-can-alcohol-rehab-be-if-someone-does-not-believe-in-a-higher-power