Jesus isn't my god, but anyone raised in this society knows the Adam and Eve story well enough to follow along with this one. Honestly, even if you didn't, the book stands on its own feet as an adventure in the classic early sf style.
I'm fascinated by the image Lewis creates of the floating lands of Venus. A world-wide ocean topped with a few islands created by plants matting together, rolling with the waves, supporting animals and trees on their surfaces. A valley one second becomes a tall hill the next, as the flexible matting forming the "ground" skims along the ocean surface. I've always wanted to live on a little island - Florida kid, you know - and I can't help but feel drawn to this image of a watery world. Too bad we know now that Venus ain't a damn thing like that. Well, maybe somewhere in the universe.
When the plot slides from that sort of almost lazy beauty into the endless days of hate and evil, I have to admit it chilled me. I have this phobia of frogs, see, so when the possessed Weston is caught torturing and mutilating the frog-like creatures of Venus, I had to put the book down for a little while. They doesn't happen often, I'm usually pretty comfortable with gross out fiction.
Also, like I said - I'm no Christian. So I never spent much time considering the Adam and Eve myth. Lewis asks us, what if Eve said no? Would the devil simply have given up and slithered off? Wouldn't he, instead, have hounded her every day of her life, lying and tricking and bribing? And, honestly, no matter how long she put him off, he had eternity on his side - one of her children would eventually give in. I'm interested in the fact that the forbidden act in Perelandra - sleeping on the "fixed land" - is only slightly portrayed as being something that would impart great wisdom by its very action. Un-Weston makes a great deal of God wanting Eve to disobey him in order to stand as her own being, but Lewis never suggests that the fixed land is "the land of knowledge" or some such parallel to the apple. Different time, different tactic?
final thought: The Christian philosophy gets a little thick on the ground toward the end, but that's the nature of the novel. I'm looking forward to the third and final book in the series, when I can get my hands on it.