Books like Out of the Silent Planet and Perelandra

Dr Ransom is a Cambridge academic who is captured whilst on a walking tour and forced into a spaceship by two men. With them he flies to Malacandra (Mars). There he escapes his two captors and discovers an amazing range of rational and spiritual creatures on the planet.In the sequel, Ransom is sent by the Eldila to Perelandra (Venus) to battle against evil incarnate and preserve a second Eden from the evil forces present in the possessed body of his enemy, Weston.