ARE YOU BORN AGAIN???

Well, how would you come to the conclusion that he's not?

I don't want to put words in your mouth, but if you're, by your own account, "baffled" that someone would adopt this belief, that does suggest that you yourself hold the contrary belief, hold it very strongly, and regard it as evidently true. Is that the case? Or is your bafflement based on something else?

Some people come to religion later in life as they are deeply unhappy with their current life and are looking for a profound change. 

Some do. But it needn't be as dramatic as "deeply unhappy" or "profound change". Some people come to religion simply because they encounter it (e.g. through a relationship) and they find it attractive or life-enhancing in some way.

The conclusion might be that this is a necessary change for the better rather than an in-depth scrutiny of whether the underlying belief system is rational.

Iscreamkone may not be suggesting that a belief in the divinity of Jesus is irrational — there's nothing inherently irrational about that belief — but rather that it is untrue. Or, at least, that he can't see a basis for accepting it as true.

I think very few people are drawn to religion (or, if brought up in religion, kept in it) out of an intellectual conviction of the truth of the precepts of the religion. That's not an especially helpful approach to religious questions, since a lot of propositions that religions make are not capable of objective verification or refutation, so if you adopt that criterion you'll be in a state of permanent perplexity and indecision. Rather people ask themselves ask themselves whether the precepts and practices of the religion in question are useful, worthwhile, make sense, etc (by which they generally mean useful, worthwhile, etc to them). If their overall experience of religion is a positive one, then they are disposed to accept the theology offered by the religion as a valid or meaningful account of why that should be so. But the theology isn't the driver here.

(Just as it usually isn't the driver when people leave religion, or switch from one religion to another.)

The religious groups that canvas door-to-door have an extremely low success rate, which perhaps suggests that what they do to propagate their religion may not be the best examplar of they things that actually do propagate religion. Similarly the number of people who become religious because they were involved with AA or availed themselves of the services of the Salvation Army or whatever is not large.

Very few people turn up through what you might call independent enquiry — they read about some church and decide "Oh, that sounds interesting — I'll go along on Sunday and give it a try". Most are there either because they are looking to make some change in their lives (which in turn means, yes, they are in some was dissatisfied with their lives as they are) or because they've had some encounter with the religion concerned — often, in the context of a romantic or family relationship — and find that it's a positive experience. Very often it's a combination of the two factors — one way or another they're looking for something, or are open to looking for something, and the relationship or connection is what leads them to look here.

Again speculation, but I think the reasons for leaving or changing religion are rather different. Some take issue with the actions or position of the church they're in. Others simply don't see the value in ongoing participation, or never opted to be a member of the church as an adult in the first instance.

By far the commonest way of leaving religion, at least in Ireland, is being brought up in religion and at some point (stereotypically, adolescence or early adulthood) falling away. My observation would be that this is mostly down to indifference — people simply don't see any value in participating, so they stop participating, And this would tie in with the stereotype just mentioned about the time of life when this happens — it's a time when your world is opening up, all kinds of new possiblities are presenting themselves, and religion doesn't seem to have anything to do with all this, so you just move on. In a way this isn't that different an impulse from the one just described — you're looking for something, but in this case religion doesn't seem to offer it.

But, yeah, sometimes it's more than indifference — it's revulsion. This can happen at any time of life and it often is connected with a negative experience that you yourself, or someone close to you, has. Coverage of clerical sex scandals or child abuse as a phenomenon is certainly damaging to the church, but what really causes people who have been engaged with religion to bail out is adverse experiences that they themselves have, or that involve people or groups that they know or care about.

No. We're not talking about a situation here in which A is trying to convince B that Jesus is divine. I agree, in that situation, it would be perfectly reasonable for B to say to A "you need to show me why I should believe this".

The situation here is that A believes that Jesus is divine, but he has not asked B to believe that. Rather, B does not understand how A, as an adult, can believe it. In this situation, A is under no obligation to justify his belief to B; if A's reasons for believing what he believes are good enough for A then B's lack of understanding is not a reason why A should abandon his belief. The implicit challenge here is actually being raised by B — "An adult cannot believe this; therefore A should not believe this". And that's a challenge that B has to explain and support.

I don't see this as a "burden of proof" thing. B doesn't actually have to prove that an adult can't believe that Jesus is divine. (If he did, he'd be snookered, because the claim is refuted by easily observed evidence — lots of adults do believe that Jesus is divine, so this is demonstrably something that adults can believe.) The discussion that B wants to have is not, I think, about whether Jesus is divine or not; still less about whether Jesus can be proven to be divine; it's about what kind of reasons we might have for believing, or not believing, that Jesus is divine, and whether they would be good reasons. This can be an interesting and productive discussion and it could even change minds (on one side or the other) but it's not a quest for any kind of "proof", so "burden of proof" is not an especially helpful way of framing it.

I recently saw a map of Germany showing the distribution of religions including atheism. The old West Germany showed areas where the different religions were popular and the old East Germany was mainly atheistic.

Why after 30 years of freedom have the East Germans and their children not “seen the light” and returned to religion?

We could equally ask ourselves why West Germans, who have been free for 70 years, have not seen the light and abandoned religion?

If we widen the scope of our enquiry a bit, and look at the rest of the post-Soviet world, we see that the picture is actually quite mixed.

• Religious identification saw a sharp decline in Russia after 1917. Not suprising, perhaps, given the transition from a political regime that strongly supported (a particular) religion to one that strongly opposed religion — there was no intervening period of religious freedom. So people do respond to religious repression by weakening their religious identification.
• In 1945, many European countries were brought into the Soviet sphere, and religion was officially repressed (though mostly not as vigorously as in the USSR itself). Before the war, most of these countries had, broadly speaking, enjoyed religious freedom, though in some there was official support or at least official favour for a particular church.
• In most of those countries religious identification declined after 1945, except in Poland, where it actually intensified. The conventional account of this is that in Poland religious identification became an expression of resistance not just to religious repression but to national repression. We could ask ourselves why this happened in Poland but not in any other country in the Soviet sphere, but for present purposes the takeaway is this; we now have to say that people usually respond to religious repression by weakening their religious identification, but sometimes they do the opposite.
• Along comes the fall of communism, and state repression of religion is ended. What happens? Religious identification rises in all post-Soviet countries except East Germany and Czechoslovakia, where it remains low, and Poland, where it actually falls (though still remaining relatively high).

It's not astonishing that, in general, religious identification rises when official repression ends. We don't have to struggle to account for this; it's just the flip side of religious identification falling when repression starts. But East Germany, Czechoslovakia and Poland look like exceptions for which we do need to account.

An account for Poland presents itself fairly easily; if some people asserted a religious identification as a way of expressing resistance to Soviet domination, once Soviet domination came to an end motivation to assert a religious identification was weakened.

East Germany and the Czech lands are not so easy to account for, but it is probably relevant that, of all the countries in the Soviet sphere, they were the most strongly atheist. That suggests there may have been cultural factors at work to keep religious identification low; it was more that just the official repression. And of course those factors may have persisted after the repressionended. And at least a part of the explanation may also be that, when religious repression came to an end, the churches were so weakened, so hollowed out, that they struggled to take advantage of this, or to present themselves in a way that would make them attractive. People participate in religion for a variety of reasons, but one of them is to connect with community. And if the churches are very marginal organisations in the community, that doesn't really work.