This is a giant set of topics. Concisely.

1. Yes, rationality and objectivity are insufficient. It is easy to find fault in others, and difficult to find it in ourselves. Therefore it is important to remind ourselves of our own cognitive biases - with examples - and have humility for our level of certainty.

2. My scientific training includes graduate level courses, but I am not a scientists. I have, however, friends who are. And have participated in scientific research.

3. As for how to judge, that's a whole can of worms. I don't recommend believing in science. I recommend tagging each belief with where it comes from, why you believe it, and how strongly you believe it. It is absolutely fine to say, "I provisionally accept X as true because I believe Y to be an expert and here is what Y said about it." But it is not fine to then certainly tell others that X is true. We do not just need to think well for ourselves. We want to encourage others to as well, so that they may return the favor.

3. No qualifications are needed to judge science. For example Feynman's Cargo Cult Science speech judged psychology to be pseudoscience. Not because Feynman was qualified in psychology. But because he identified specific reasons to think them such. Psychologists largely dismissed his criticism "because what does a physicist know about psychology". But about 40 years later his claim that lack of replication threw psychology into doubt was put to the test, and the result is the https://en.wikipedia.org/wiki/Replication_crisis.

4. Scientists in general do not live up to their professed ideals. One major problem is a tendency to take sides, and then irrationally defend our side more strongly than the data suggests. So scientists take sides on the ideas that they have come to believe, and reject contrary evidence. The result is that new ideas only get a chance when existing scientists die. Thus the saying, "Science progresses one funeral at a time." Which https://pubs.aeaweb.org/doi/pdfplus/10.1257/aer.20161574 shows quantitative evidence for.

5. This is, sadly, not a small effect. To give two well-known examples, read https://www.amazon.com/Trouble-Physics-String-Theory-Science.... And separately do your own research into how many billions have been put into the Amyloid Hypothesis in Alzheimer's research, on insufficient evidence.

6. This goes doubly for scientific organizations set up by the government. In addition to normal scientific biases, they suffer from political biases and corruption. For example the FDA contributed greatly to the opioid crisis. See https://journalofethics.ama-assn.org/article/how-fda-failure... for more. From other reports, one of the prime causes is a revolving door where compliant regulators approved questionable treatments in return for walking through the revolving door into high paying jobs at pharmaceutical companies. This form of bribery is both legal and sadly common.

7. In addition, both science and scientists suffer from other cognitive biases. For example I believe that our over the top COVID policies are a direct result of overreaction against everything Trump says. It is worth comparing US policies with much more balanced German policies, that have produced substantially better results with less cost to, for instance, children's education.

Sorry, went on a rant.

Now to religion.

You are right that my desire is to test my own beliefs, and not challenge the others. You're also right that evidence is what gets discussed more than belief. However the point of discussing evidence is that by laying out why I believe what I believe, I make it easy to challenge weak spots in my reasoning.

But when I analyze beliefs that others hold, I tend to apply similar standards.

For example you brought up Jesus. We know about Jesus from the Bible. I do not pretend to expertise in the Bible. But the following is fairly widely accepted as probably true.

There are 4 Gospels. They are not independent. Matt and Luke copied from Mark, and probably a missing text known as Q. John is separate, and conflicts with the first three. All were written down from oral traditions some decades later. Within early Christianity there were many conflicting versions of these and others. About 300 years later, at the First Council of Nicaea, definitive versions of these were chosen. And that has become the modern Bible.

Now your point of view is that of a believer. But try to put yourself in the viewpoint of a nonbeliever, and consider that information as follows.

By all accounts, early Christianity was a cult. The world has had many cults. Some, like Islam, have grown into great religions. Most have not. Cults have not stopped being created. For example see Hare Krishnas and Scientologists for well-known cults that formed recently.

Modern cults demonstrate that the weirdest of ideas, on pretty flimsy evidence, can attract people from a wide swathe of society. I also put little evidentiary weight on their religious text. If this is how I treat the claims of modern cults, how should I treat the claims of early Christianity? If I treat them the same way, I'm left with not much confidence that Jesus actually did the things claimed in the Bible.

And on this weak evidence I am supposed to accept very strong claims. That he was the son of God. That people can be healed by casting out demons. That he could turn water into wine. And so on.

Extraordinary claims require extraordinary evidence. And this does not strike me as extraordinary evidence. It seems dubious to me that religious people truly are rationally accepting these claims on this evidence.

Indeed, the religious people that I know, do not belief for such flimsy reasons. They believe that they have a personal relationship with Jesus. That everyone is offered that. And that is the true source of their belief. There can be contradictions in the Bible and it does not matter, because you experience Jesus.

It is both trite, and true, to say that I have no such personal relationship. What is more interesting is that I'm aware of how to create a state where I would feel otherwise. But the techniques that I would use to do so could just as easily lead me to having a personal relationship with the Muslim version of God, Krishna, or a pagan Jupiter of the form described by Marcus Aurelius in Meditations.

Therefore, as a non-believer, I see the strongest evidence that motivates religious people as a self-created mental state. On what evidence can I tell that apart from a genuine relationship with God?

The first is what I just said. That I could create similar mental states for a wide variety of beliefs. The second is that different Christians throughout history have found that their personal relationship with God tells them very contradictory things about doctrine. It gets complicated because it got intertwined with politics, but for example in the 30 Year War, an estimated 30% of Germans got slaughtered over disagreements about things like how exclusive the Pope's access to the keys to the kingdom is.

And what people believe, changes. For over 1400 years, Christians universally believed that the commandment against usury applied to them. After all, didn't Jesus reinforce it by throwing the moneylenders out of the Temple? This is the historical reason why Jews are associated with moneylending. Jews interpreted the commandment as only applying to other Jews, so they could lend to Christians. While Christians couldn't lend to Christians.

But then...the commandment disappeared from Christianity. Few Christians today are particularly aware that Christianity once had such a commandment. Fewer still could tell you why Christianity no longer does.

As an outsider, I take this as evidence that a Christian's personal relationship with Jesus is an invented experience. Christians are only told by Jesus what they already think should be true. Which doesn't fit with what I would expect if they actually had personal relationships with an actual external entity.

I therefore find myself not compelled to acceptance of Christianity. And, likewise, I do not find religious accounts of the Flood to be evidence on an equivalent level with, say, sediment cores in lakes.

Incidentally I have personally known people who analyze such sediment cores. Though theirs were much less impressive than the Japanese example. In particular the limited history of the sediment cores were consistent with other evidence of the area having been covered with glaciers just a few thousand years before.