Of course context matters, but one reason it matters is because people abuse it. There is a legitimate complaint to be made when someone distorts or mangles an isolated quote to say something completely different from what the author intended. Here’s an infamous example: the creationists’ favorite quote from Darwin’s Origin.
To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.
They love it because all they read is
natural selection…absurd in the highest degree, and think they’ve got a slam-dunk debunking straight from Darwin himself. This is a case where you must read the rest of the context, because what he’s doing is setting up a rhetorical case that selection seems absurd, but what follows is a whole chapter in which he explains all the gradations and intermediate steps in the evolution of the eye. And of course all it takes is the next two sentences to make it clear that he’s saying exactly the opposite of what creationists want him to say.
When it was first said that the sun stood still and the world turned round, the common sense of mankind declared the doctrine false; but the old saying of Vox populi, vox Dei [“the voice of the people = the voice of God “], as every philosopher knows, cannot be trusted in science. Reason tells me, that if numerous gradations from a simple and imperfect eye to one complex and perfect can be shown to exist, each grade being useful to its possessor, as is certain the case; if further, the eye ever varies and the variations be inherited, as is likewise certainly the case; and if such variations should be useful to any animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, should not be considered as subversive of the theory.