This is inspired by Michael A. Burstein's Reading Writers You Hate, but it comes from things I've been pondering for most of my life. The quick take: There are no saints. If you wish to encounter new ideas, you have to read the works of flawed people. Your job as a reader is to forgive failures and acknowledge successes.
And sometimes, your understanding of a writer will simply be wrong because you don't have the knowledge to truly understand their work. Huckleberry Finn may be the greatest book written about racism, but because Twain couldn't create didactic art if his daughters' lives were at stake, many readers miss what the story's truly about, the willingness of a boy to abandon everything he has been taught in order to free a black man he has come to love as his equal.
Lord Acton's a very flawed writer who I greatly admire. His most famous quote should be known by everyone: "Power tends to corrupt, and absolute power corrupts absolutely."
On the subject of power, he's brilliant:
"Great men are almost always bad men, even when they exercise influence and not authority: still more when you superadd the tendency or certainty of corruption by full authority."
"Every thing secret degenerates, even the administration of justice; nothing is safe that does not show how it can bear discussion and publicity."
But Acton was a capitalist, a racist, and an imperalist. He wrote, "The Celts are not among the progressive, initiative races, but among those which supply the materials rather than the impulse of history, and are either stationary or retrogressive. The Persians, the Greeks, the Romans, and the Teutons are the only makers of history, the only authors of advancement. Other races possessing a highly developed language, a speculative religion, enjoying luxury and art, attain to a certain pitch of cultivation which they are unable to either communicate or to increase. They are a negative element in the world… The Chinese are a people of this kind… So the Hindoo… So the Slavonians… …To this class of natives also belong the Celts of Gaul… The Celts of these islands [Great Britain], in like manner… Subjection to a people of a higher capacity for government is of itself no misfortune and it is to most countries the condition of their political advancement… Theorists who hold it to be wrong that a nation should belong to a foreign state are therefore in contradiction with the law of civil progress."
In short, on those subjects, he was an idiot. But he was still right about the nature of power and the importance of open government.
ETA: Just realized I forgot to conclude this, so: In reading, as in life, be a cafeterian, choosing what's useful and leaving the rest.