It's a little more complex than that. A lot more. Enlightenment doesn't necessarily involve developing a lot of intellectual knowledge. Negative deeds are punished, and unlike in Christianity there isn't a "free" way out, Karma can be overcome but through our own efforts. Yes, there are notions of Divine Grace as well, especially in the Bhakti traditions, in fact in all traditions in the sense that ego can't overcome ego so there has to be another force involved. In Buddhism the cause of hell is anger, the Preta realm intense desire and greed, the animal realm ignorance.
I would recommend actually making serious studies of the Eastern religions, not only in order to make correct statements about them, but also because you might find in them a kind of reasoning which is basically alien to the Abrahamic traditions. In the Abrahamic religions things begin with the enigmatic and poetic statements of prophets, philosophies developed as a kind of secondary element. The Eastern teachings are in themselves philosophical, founded on logic and upon debate with other traditions to establish correct tenet systems.