You are both right and both wrong. Buddhism is a religion because it teaches a soteriology (salvation) that is based on faith (namely in the three jewels). It's a different type of religion to those with which we are most familiar in the West, but it is a religion nevertheless. All religion involves philosophy but philosophy does not need to involve religiosity. It is that simple. There is no creator deity, no all powerful entity. Devas (gods) are usually not taken literally and if they are, they are subject to karma and rebirth - you could be reborn in a god realm and then be reborn elsewhere again once your karma is exhausted.