It’s one thing to say that Jesus lived, walked the Earth, had teachings to share with people, and got crucified by the Romans. It is an entirely different thing to say that he turned water into wine, healed the blind, was born of a virgin, and was raised from the dead. Historical claims are completely different from supernatural claims.
The world we live in is all we know. When someone says that Jesus was born from an immaculate conception, all we have to do is look at all the births that have ever happened, and see what percentage of them were immaculate. It turns out that that percentage is zero. If someone claimed immaculate conception today in whatever circle, they would not be taken seriously. How could one even prove that a conception was immaculate (unless we had a microscope focused on the egg in her body and saw it spontaneously gestate without sperm)? In order to believe such a thing, you have to not require any evidence. Christians take pride in having faith, but I don’t think there’s anything good about it. Not requiring evidence for your beliefs leaves you much more open to accepting false ones. For example, if the Guiness Book of World Records accepted every claim without independently verifiable evidence, the book’s credibility would plummet, and no one would read it. The literal truth of the miracles of the Bible works in the exact same way.
Even miracles that multiple people claim to have seen are still without strong evidence. Many people have claimed to see Bigfoot, the Lochness monster, leprechauns, and other things that sensible people don’t believe in. No one takes these claims seriously because we realize that personal testimony is the lowest form of evidence. Why should the claims of the Bible receive different treatment?