It could mean anything.
If you believe in god, and the god you believe in is real, but your views on heaven are wrong you might not see the people you love there anyway.
If you believe in god, and there is no god, your belief in god won't make any difference to anything because you die and become worm food.
If you believe in god, and backed the wrong god, the future could be anything.
If you believe in god but don't do what that god requires to get into heaven (whether through deliberate intent or failing to make the grade) you may not see loved ones in heaven because you didn't make it to heaven.
If you believe in god and do everything right to get to heaven there's no guarantee your loved ones will be there anyway.
Small g on god intentional, to refer to any deity because the concept is largely generic.