It is often claimed that Christianity is good for societies, and good for men - in the sense that societies are better places to live-in and Men are better behaved.
But I was never much convinced by this; I cannot really see a qualitative change-for-the-better in history - dating from the time of Christ; nor in Men who become Christian.
There seems to be evidence on both sides - and furthermore, it doesn't seem like the kind of claim where evidence should be relevant. Should we be basing our faith on our knowledge of 'history' and how we interpret it?
I don't think so - and I don't find any ground of assumptions from-which Christians and non-Christians would be likely to agree on the objectivity of evaluations about better societies and better Men.
After all, there are massively opposed views about how good a Man someone was. Was Winston Churchill the greatest ever Englishmen (he was voted number one in a national poll), or was he an incompetent fool, motivated by evil (as many have always argued)?
And the same applies to societies. For example, there are plenty of people - apparently - who think that England in 2021 is overall a 'better' place than it ever has been - and is getting better. How can someone like me even begin to argue objectively with someone who reaches such an evaluation?
Anyway, when I read the Fourth Gospel ('John' - our primary text on Jesus's life and teaching) - I don't see any claim that Christianity makes people better; and the Gospel is unconcerned by the valuation of nations, empires.
Christianity is about following Jesus to resurrected life eternal - and any relationship to changes in human behaviour is very indirect; indeed Jesus goes to considerable lengths to argue that good behaviour is Not the point; and that sinners can be saved by faith.
To be clear; I believe that being a Christian can and should be of immense benefit to living life as it should be lived; indeed I regard it as essential for a proper understanding of life.
Yet, I do not see any strong links between this and desirable-behaviour.
However, while I doubt any general claim that Christianity is an effective means of intrinsically-beneficial psychological and social control; it does seem very obvious indeed that the loss of Christianity - apostasy in individuals or nations - is very bad for these things.
So bad, in fact; that the capacity for recognizing and knowing badness is itself lost; and individuals, and societies, are set-adrift in a sea of incoherence which they cannot notice, therefore cannot escape-from.
People, societies, have lost values and the capacity for values. Therefore their values are arbitrary and externally-imposed; by others who have, themselves, at best lost values.
(But at worst - that is to say in reality by my judgment - a world where arbitrary values are imposed by those whose values are the inversion of Good.)
At the deepest level, this is not really to do with the removal of religious constraints (as is usually argued); but is more more fundamental and dangerous a phenomenon. It is to do with the removal of faith; meaning those metaphysical assumptions that enable both coherence of thinking, and hope for life.
When people really believe - believe so deeply that they are unaware of this belief - that they are adrift in a meaningless, purposeless world; where they themselves are just a temporary irrelevance --- then we get the kind of objectively-dysfunctional people and societies we see all around us.
And that is Not 'a matter of opinion'; but a truth - a truth for those who are capable of coherence.