Final answer:
C.S. Lewis and G.K. Chesterton were the two great apologists for orthodox religion in the 20th century, known for their influential defenses of Christianity.
Step-by-step explanation:
The two great apologists for orthodox religion in the 20th century were C.S. Lewis and G.K. Chesterton. Both Lewis and Chesterton were well-known for their writings, which defended Christianity and argued for the rationality of religious belief during a time when atheistic philosophies were gaining traction.
C.S. Lewis is best known for his works such as 'Mere Christianity' and 'The Chronicles of Narnia,' which combine imaginative fiction with Christian apologetics. On the other hand, G.K. Chesterton, a prolific writer and critic, penned influential works like 'Orthodoxy' and 'The Everlasting Man,' which offered a spirited defense of Christianity against the tide of modern skepticism. Both authors were instrumental in engaging positively with the challenges to Christian theism in their time and continue to be influential figures in religious discourse.