Of course helping others and being active is the key to maintaining sobriety.
I currently go to 7 to 12 meetings a week, I have chaired, lead, got donuts, set up, cleaned up, picked up people, dropped off people, sponsored, etc etc and I have only been in the program about 11 months.
I can now tell which people are not going to make it because they are just taking up space and fooling themselves - I have been trying to help out this 68 year old dude that has been in and out of AA since 1988 - he just can't get it.