Yes, but what I expected was...um...atheists who were better than most, who had arrived at atheism through two-sided discourse.

Bob Altemeyer asked college students about this, some of whom had a strong allegiance to 'traditional' authority and some less so:

Interestingly, virtually everyone said she had questioned the existence of God at some time in her life. What did the authoritarian students do when this question arose? Most of all, they prayed for enlightenment. Secondly, they talked to their friends who believed in God. Or they talked with their parents. Or they read scriptures. In other words, they seldom made a two-sided search of the issue. Basically they seem to have been seeking reassurance about the Divinity, not pro- and con- arguments about its existence-- probably because they were terrified of the implications if there is no God.

Did low RWA students correspondingly immerse themselves in the atheist point of view? No. Instead they overwhelmingly said they had tried to figure things out for themselves. Yes they talked with nonbelievers and studied up on scientific findings that challenged traditional beliefs. But they also discussed things with friends who believed in God and they talked with their parents (almost all of whom believed in God). They exposed themselves to both yea and nay arguments, and then made up their minds--which often left them theists. In contrast, High RWAs didn’t take a chance on a two-sided search.

Despite what he says at the end, this "RWA" attitude correlates with religion - and Less Wrong seems to have unusually low RWA in any case. We also have a certain tendency to read books. You should therefore expect some of us to know the 'strongest' arguments for religion, and consider them bad. Don't just assert that we don't. Name an argument and see if we know it!

On a related note, you seem statistically in danger of losing your faith. If you want to keep it, you should use some form of Crowley's general method of religious devotion. While I failed to produce a vision of the Goddess Eris in the short time I allotted to this method, a kind of 'sophisticated' Discordianism did come to seem reasonable for a while.

A rationalist ought to have heard arguments and evidence that challenged his (dis)beliefs, and have come out stronger because of it.

A rationalist

You keep using that word...

In Avoiding Your Belief's Real Weak Points, Eliezer says:

There is a tradition of inquiry. But you only attack targets for purposes of defending them. You only attack targets you know you can defend.

In Modern Orthodox Judaism I have not heard much emphasis of the virtues of blind faith. You're allowed to doubt. You're just not allowed to successfully doubt.

The point being that this is exactly not how rationality is supposed to work. If you hear a convincing argument, you should update your belief in the direction of the belief the argument argues for. If you update in the other direction ("come out stronger"), then either it's not a convincing argument (by definition), or you're doing it wrong.

I don't know what you think a "strong argument" is. Arguments are not weapons, with a certain caliber and stopping power and so forth, such that two sides might go at each other with their respective arguments, and whoever's got the most firepower wins. That's not how it works.

An argument may be more or less persuasive (relative to some audience!), but that depends on many things, such as whether the argument hits certain emotional notes, whether it makes use of certain common fallacies and biases, or certain commonly held misconceptions; or whether it is structured so as to obscure its flaws; or even whether it's couched in fancy or beautiful sounding language.

Whether an argument is correct (i.e. valid and sound) is another matter entirely, and may have little to do with whether the argument, in actual fact, tends to persuade many people.

We here at Less Wrong have seen many arguments for the existence of God, many of which are found to be persuasive by many people who are not aware of their flaws (by "their" I can mean the arguments' flaws, or the flaws of the audience, i.e. cognitive biases and so forth).

All of those arguments are wrong (invalid, unsound, full of fallacies, etc.). That's what we mean when we say they're not "good" arguments.

Oh, and another thing:

The optimal situation is that both sides have strong arguments, but atheism's arguments are stronger.

What do you mean, "optimal"? Look, for any question where there is, in principle, a correct answer (which might not be known), the totality of the information available to us at any given time will point to some answer (which might not be the correct one, given incomplete information). Arguments for that answer might be correct. Arguments for some other answer will be wrong.

Why would we expect there to be good arguments for the wrong answer?

Yes, but what I expected was...um...atheists who were better than most, who had arrived at atheism through two-sided discourse.

What does two-sided discourse look like, in your view?

The optimal situation is that both sides have strong arguments, but atheism's arguments are stronger.

Why is that the "optimal" situation ? Optimal according to what metric ?

who had arrived at atheism through two-sided discourse.

I personally never was religious, but AFAIK I'm an outlier. Most atheists arrived at atheism exactly in the way that you describe; others got there by reading the Bible. I don't have hard data to support this claim, though, so I could be wrong.

I think the holy books are kind of hampering mainstream religions, to be honest. We live in a world where pictures of distant galaxies are considered so mundane that they hardly ever make the news, and where the average person carries a supercomputer in his pocket, which connects him to a global communication network that speaks via invisible light. The average person typically wields this unimaginable power in order to inform his friends about quotidian matters such as "look at what I had for lunch today".

Against the backdrop of this much knowledge and power, the holy books look... well... kind of drab. They tell us that the world is a tiny disc, covered by a crystalline dome, and that the space outside this dome is inhabited by vaguely humanoid super-powered beings who, despite having the power to create worlds and cover them with crystalline domes, actually do care about what we had for lunch today. Hopefully it wasn't ham. Gods hate ham.

I understand that most theists don't take their holy books quite that literally, and that it's all supposed to be a big allegory for something or other, but still, it's hard to get excited about a text that didn't even get the shape of the Earth right.

That's my own personal perspective, at least.