H.P.
Okay, you are asking the wrong question. You're not going to motivate your boyfriend to get a job, but that's not your issue with him. It's a symptom. He doesn't respect/love you and himself enough to act on it. You can't create or motivate that in someone. Either it's there or it's not. YOU need to make decisions about YOUR life and what you need to care for your baby. Why are you still living with this guy? That's the question you should ask. Why do you continue to put up with someone in your life who brings nothing to it?
If you hope for any kind of good life with him, you should hold him accountable. You can't push him to step up to the plate; but if he will do it at all, you will first have to stop making it so easy for him not to. He can obviously get by with no money where he is, so put him somewhere else, somewhere where he'll be forced to get up off his butt. Stop making his surroundings so cushy. He hasn't earned the right to pay no bills, yet you're allowing it. It won't stop until you are truly ready for it to stop.