If atheists did not have their snappy slogans, they would have nothing at all. One of those snappy slogans is "extraordinary claims require extraordinary evidence". The irony of this claim is that it is, itself, extraordinary. The word "extraordinary" is basically a synonym for unusual. Since this is not only one of the few times a person would make such a statement, but also one of the few times people would actually apply its logic full stop, it really is an extraordinary claim.
The world is a huge place, filled with more than 7 billion people. Because of this, you're actually going to find all sorts of extraordinary claims, none of which require extraordinary evidence. They require the normal standard of evidence required for any claim. If you refuse to believe a claim that is true, yet extraordinary, in spite of solid evidence, you aren't being reasonable, you're being stubborn.
Furthermore, ordinary claims can be completely and utterly false, yet these get swallowed without a second glance. Take, for example, the claim that blood is blue when it is without oxygen. Have you ever seen a drop of blue blood? Of course you haven't, blood isn't blue! Yet, this claim is so common, even many biology professors (including my own) taught it as fact.
Ironically, Christianity doesn't even make many extraordinary claims. In fact, we share some of our core claims with the majority of humanity. It is perfectly ordinary to believe in a creator god with the ability to supernaturally affect the natural world. Atheism is actually a minority, both historically and in the modern day. That makes atheism the extraordinary claim. So, what we're looking at here is people making an extraordinary claim, and defending that extraordinary claim with another extraordinary claim that "extraordinary claims require extraordinary evidence".
But this phrase is damning in more ways than just its hypocrisy. Not only is it self refuting, and liable to backfire, but it is also a tacit admission that we have ordinary evidence.
See, as I already stated, even extraordinary claims are subject only to a reasonable standard of evidence. Of course we should not be gullible, but we shouldn't be extraordinarily sceptical either. If, for example, several reliable witnesses warn you that there is a crocodile in the local canal, and said crocodile later chomps your chihuahua, that isn't the fault of the witnesses, but rather, it is yours, because you were too stubborn to know how to pick your battles.
Evidence matters. Regardless of the claim being made, it is the duty of the reasonable mind to investigate it honestly. Indeed, even the Bible says "test all things". But it continues to say "hold on to that which is good" (see 1 Thessalonians 5:21). Thankfully, Christianity passes that test with flying colors, with ordinary evidence. That is, the kind of evidence with which we test other claims.
One great evidence for Christianity that has stood the test of time is the reliability of its witness testimony. Whichever way you cut the cake, the Bible is a historical document (or rather, a collection of historical documents), much like any other. Thus, it can be examined like one. What we see when we examine it is that it is not just the drunken ramblings of some iron age goat herders. There are a plurality of witnesses from a wide range of backgrounds, all testifying to one consistent story. Even the types of witnesses relied upon are not what you would expect from a made up story of that era.
I specify "of that era" because the Bible was written in a very different time. We're not talking about 2020, where women are seen as equal (and, in some cases, superior) to men. We're talking about a time when women were viewed as weak in both body and mind. A time when if you said "women found Jesus' tomb empty", sceptics would pounce upon that to mock Christianity. Sceptics like, for example, the Greek philosopher, Celsus.
Even the very authors to whom each gospel account is attributed makes sense if they're genuine, but not so much otherwise. Pseudepigrapha (falsely attributed writings) tended to be attributed to more prominent witnesses, such as Judas, or Thomas, yet the gospels are attributed to "nobodies", such as Matthew, or Mark. Peter is even said to have had a hand in Mark's gospel, yet Mark is still identified as the author.
Luke is another author, a physician, and a historian. This man was no joke. He carefully investigated the events he described, all of which happened within his own lifetime. He could very well have spoken to all 11 of Jesus' Apostles, and several other key figures.
John's gospel bears several marks of being the words of an eyewitness. For example, he notes himself as being closer to the cross, which gives him access to information other eyewitnesses didn't have.
There are many other evidences for the reliability of Scripture, from the micro to the macro. Far too much for me to sum up in a blog post. Suffice to say, even if you don't want to admit Christianity is true just yet (which is fair enough, go do more study and you'll eventually see that it is), we have plenty of ordinary evidence. Undesigned coincidences in the gospel narratives, name studies matching the era, geographical descriptions that only a local witness would know, the "minimal facts" argument, these are all just a few things that convince the reasonable mind that Jesus is Lord. Are they extraordinary? No. We use things like this to examine many other claims. But they are evidence, and so to so brazenly raise your standard of evidence by saying "extraordinary claims require extraordinary evidence" is unreasonable at best, but also exposes the fact that you know the reasonable standard has been met.
The next question, therefore, is why do you show such resistance? What benefit is there to clinging to lies, especially to the extent of presenting the illusion of wisdom? The obvious answer is sin. We oppose God because He opposes us. We don't like His "thou shalts" and "thou shalt nots". So we dismiss His existence in order to dismiss His authority. As it is often said, an atheist can't find God for the same reason a criminal can't find a police officer. But the officer can find them, and a time is coming when God will call the atheist into judgement. In this case, there will be no extraordinary evidence for the atheist's ordinary sins. God simply knows the truth, and the truth will condemn the atheist.
This, however, is not His desire. Scripture tells us that God takes no pleasure in the death of the wicked. Just as the wicked will take no pleasure in their own death. A mutually beneficial solution, then, is to simply follow the evidence where it leads. It will lead you to the cross, which will lead you to faith, which will lead you to repentance, which will lead you to salvation.