Drama drags bands down. If he doesn't want to be there, let him go. You have plenty of time to find someone else. And since you're starting off, you'll need to get used to people coming and going 1) as their tastes change, 2) as they grow up and start making other choices, 3) as they go through the various identity crises associated with adolescence, 4) as they move away for schools/college/jobs/families. Shit happens, it'll be ok, just stay dedicated to your own music.