Every so often, social media supports a round of comment picking up on the question of the many faiths and religions there are and have been overtime. One such ‘poster’ was endorsed recently by the American Atheist organisation (which by the way does wonderful work in support of atheist views in public and political life, including the highly desirable electability of atheist politicians in that most paradoxical of countries).
But here is the post, originating with comedian Ricky Gervais:
What is going on here hides two unstated assumptions that turn the rather silly quote into an aspirational argument for the illogicality of religious belief:
(1) Every religion teaches that it is correct and the other are wrong
(2) Given an object or aspect of external reality, people will have the same narrative concerning it
This is supposed to be strong evidence against any external reality that anyone has ever called ‘God’ because by syllogistic reasoning, the existence of God would activate (2), which is in conflict with (1). However, neither (1) nor (2) is true. I will briefly treat both in the following (though necessarily at greater length than the post itself). For this is one of the common fallacies of atheism (at least the popular kind) that would be helped by some scientific thinking and experience.
One thing ought to be made quite clear as a preliminary – that the implied claim of the lazy ‘3000 religions’ language is that there are thousands of arbitrarily different religions in existence with essentially no common features. This is not so – the vast majority of the world’s population (which is still in overwhelming majority religiously affiliated) are Christians (31.4%), Muslims (23.2%) and Hindu (15%) . Christianity, Islam and Judaism all root themselves in a common history of revelation beginning with Abraham, share a great deal of scriptural, theological and ethical teaching and practice – and furthermore recognise that in their teaching (see below). Together with basic (Vedic) Hinduism all are mono-theistic and creational. So we are not at all faced with the smorgasboard of random religious proliferation you suggest at all.
So on the substance of (1) the rhetorical sleight of hand here is to force evaluation into a 1-bit ‘right or wrong’ measure. To a scientist, incidentally, this trick rings warning bells a mile off – we never get to be black and white, right or wrong, about the world – we get better or poorer accounts of it, and a sure sign of a desperate move from a weak position is that its proponents start demanding 1-bit status from their opposing theoretical camps. So, as C.S. Lewis once put it , ‘If you are a Christian you do not have to believe that all the other religions are simply wrong all through. If you are an atheist you do have to believe that the main point in all the religions of the whole world is simply one huge mistake. If you are a Christian, you are free to think that all those religions, even the queerest ones, contain at least some hint of the truth. When I was an atheist I had to try to persuade myself that most of the human race have always been wrong about the question that mattered to them most; when I became a Christian I was able to take a more liberal view’.
The recognition of both truth and value in other religions is also formalised (in those traditions that like to formalise things). The relevant Roman Catholic statement is ‘Nostra Aetete’, for example  which contains the following observation: ‘From ancient times down to the present, there is found among various peoples a certain perception of that hidden power which hovers over the course of things and over the events of human history; at times some indeed have come to the recognition of a Supreme Being, or even of a Father. This perception and recognition penetrates their lives with a profound religious sense.’ Islam, too, has a tradition of respect for the ‘People of the Book’ in both Koran and non-Koranic teachings  which played out historically, for example, in the degrees of Mohammed on peaceful relations with Jews and Christians onwards.
There is furthermore a long tradition of the philosophy and anthropology or religion that carefully identifies commonalities and differences in religions. The leading-edge original work here is probably best exemplified by Kant (as in so much else) who in his ‘Religion’ identified an inner structure which he called the ‘pure rational system of religion’. This is a common core that speaks, in differentiate language, of the human state of corruption and need of redemption in some form or other .
One example of important detail in this tradition of study is the common appearance of the motif of a dying and rising god . This was instrumental in the development of Lewis’ realisation that one could countenance a ‘True Myth’ as a source of a wide mythological tradition – namely the incarnation of God in Jesus, his death and resurrection as the healing move in answer to the (equally commonly felt – see Kant) need of redemption.
Finally I should add that all this is true in personal experience. I have three times now been privileged to be a participant at inter-faith discussion of science and religion held at CERN under the auspices of its former Director Rolf Heuer. These 3-day symposia of discussions between Jewish, Muslim, Janist, Buddhist, Hindu, Christian and atheist scholars and scientists have been living evidence of the mutual respect, learning and valuing that is at the heart of a response to God.
That’s probably enough to show how mistaken proposition (1) is. As for (2) hopefully this doesn’t need to take as long. History of science , anthropology , cognitive neuroscience  all show us that consistently a common externality does not give rise to a common internal human experience nor a common narrative in communities. We bring our own experience, stories, symbols, language to bear on the interpretation of the external world both at the level of individuals and communities. So very radically different accounts of external experience with a common source not only may be different but are expected to be different.
Long-exposure photograph of the Milky Way looking towards the centre of our galaxy
Different cultures have as many stories to tell about the Milky Way, rainbows, the nature of animals, the musical possibilities of sound, as there are cultures. As ideas develop, thinking advances, communication enriches, these change to be sure, and in the area we call ‘science’ do converge to some degree. But timescales for this vary radically. In religion I think the timescales are very much longer than in chemistry.
One reason for the divergence of explanatory narrative about experience is that by ‘explanation’ we mean typically by linking one object or mode of behaviour to another. So explanation becomes especially problematic for aspects of experiences reality that are unique (such as consciousness). McGilchrist (op. cit. – a wonderful book by the way) is very good on this. So there is and cannot be an expectation that as unique an entity as God would give rise to a clearly unequivocal narrative across humanity – quite the opposite in fact.
So in conclusion, since both of the assumptions behind the one-liner are demonstrably wrong, as are a number of the implied co-assumptions, it leads us to a very different place than its author and followers think it does. Far from adding weight to any argument that Christianity is incredible, it exemplifies the difficulties that atheism has in accounting for a universal human experience and response, and the disingenuous tactics that its proponent need to deploy, I am sorry to say, to sustain its appeal, ignoring centuries of reflection on precisely the questions it claims as shiny and new and worthy of the little child who points out the nakedness of an emperor.
The Emperor is naked of course – he hangs there, creator of the stars, stripped and suffering on a cross – ‘foolishness to the Gentiles’  and offering forgiveness and life.
You couldn’t make it up 
 Pew research Centre statistics http://www.pewforum.org/2015/04/02/religious-projections-2010-2050/pf_15-04-02_projectionstables8/
 C.S. Lewis, Mere Christianity, Harper-Collins, New York (2001), p35
 Nasr, Seyyed Hossein (1973). Sufi Essays. State University of New York Press. p. 139.
 Kant, Immanuel, Religion within the Boundaries of Mere Reason. (1793). George Di Giovanni (trans.), 57–215.
 Lee W. Bailey, “Dying and rising gods” in: David A. Leeming, Kathryn Madden and Stanton Marlan (eds.) Encyclopedia of Psychology and Religion (2009) Springer, pages 266-267
 J. Brooke and G. Cantor, ‘Reconstructing Nature’, T&T Clarke (1998)
 K. Harstrup, Anthropology and Nature, Routledge (2013)
 I. MacGilchrist, ‘The Master and his Emissary’, Yale University Press (2010)
 St Paul, 1 Cor 1:23
 C.S. Lewis, Mere Christianity, once more