Sometimes one has to respond to people who believe that a scientific theory currently considered valid is wrong. Something like: "I'm skeptic about the Moon gravity causing the tides."
There are three ways to deal with this: the good, the bad, and the ugly.
The good way
The appropriate skeptic response to people questioning currently valid science is 'let's look at the evidence.' That's it.
The good way has advantages: occasionally the questioner may be right and the responder will learn something; in the other cases, it's easier to persuade the questioner if the responder starts by taking the question seriously.
Reliance on evidence (observation and/or experimentation) is the foundation of science and skepticism, so there should be no question about skeptics responding this way. Alas, many don't, since to them science and skepticism/atheism are just identity products.
The bad way
The bad way, the most common response by "skeptics," "atheists," and people who "love" science (but don't learn any), is to say 'you can't question scientific facts.' There are some variations, like 'all/most scientists agree' or 'this source that I trust says.'
Besides being precisely the opposite of what science is (pace Feynman: science is the belief in the ignorance of experts), answering this way helps the cause of those who say that science is just another form of dogma (or faith).
Most "skeptic/atheist/effing love science" prefer the bad way because to use the good way they must know what they're talking about. And many of them don't. For example, take this pitiful response to Bill O'Reilly. Carl Sagan would have said "it's an effect of the Moon gravity" before O'Reilly finished asking. But the president of the American Atheists apparently slept through that 5th-grade science lesson.
The ugly way
The ugly way is to impugn the motives of the questioner, launch a number of ad-hominem attacks, and block or ban them from participating in any further discussion. This is the response of many "skeptic" and "atheist" groups, platforms, and strident advocates.
(Of course, in my case, it was more of a 'how dare you pleb correct me, professor doctor scientist?' which is a type of pathology you meet in certain corners of academe.)
Richard Nikoley had a similar experience after making a related point using more colorful language.