Atheists often use miracles in an attempt to prove Christianity is false. They point to miracles, most commonly the virgin birth, the resurrection and especially Satan's use of a talking snake in Genesis 3, and claim that these things are scientifically impossible, and therefore anyone who believes the Bible must naturally reject science.
However, these things are never claimed to be the norm. They are specifically noted as being supernatural, not regular occurrences. In other words, yes, of course they're unscientific. That's the whole point. But what the atheist misses is the fact that in order to believe in the supernatural, we must believe in the natural first. A miracle is a violation of natural law, so if there's no natural law to violate, there can be no miracles. In other words, rather than proving Christians don't believe in science, Christians have to believe in science.