Some people today think that it is ignorant to believe in Satan. Well, if you feel like that, I just ask you to look at the world and at yourself and try to explain some of the things that happen, both within you and in the world, apart from the biblical teaching about Satan and the hosts and powers of evil, these malevolent influences that are unseen in the spiritual realm.
Our Lord and Savior himself said, “As it was in the days of Noah, so shall it be also in the days of the Son of man. . . . Likewise also as it was in the days of Lot. . . .” (Luke 17:26, 28). He spans the centuries; he lays down the proposition that because of sin and the Fall, mankind as mankind is going to be no different at the end of history than what it was at the beginning. Therefore, nothing is such an utter travesty of the Christian gospel as the suggestion that because it is preached, each generation will be better than the previous one, and the world will reform and improve, until everything that is evil and wrong will have been banished and ultimately all will be perfect.
The gospel never teaches that; it asserts the exact opposite. I do not apologize for saying that the Bible’s view of history is profoundly pessimistic. Of course, that is why the Bible is not popular and has not been so during the last hundred years. Evolutionary theories and hypotheses are very optimistic; they all tell us that the world is going to be better and better and that mankind is evolving and advancing. Philosophers always want to be optimistic if they can be, and thus they paint this picture of improvement. And, of course, if you believe them, you cannot like the Bible because its realism contrasts sharply with these optimistic ideas.
D. Martyn Lloyd-Jones, Let Not Your Heart Be Troubled, p. 95-96