Jainism, morally speaking, strikes me as the "ideal" religion for the human race as a whole. It's essential teachings are complete non-violence and pluralism.
However out with morals, I do not think dogmatically speaking any single religious philosophy could even in principle draw adherence from everyone and nor would I consider this too be desirable.
I would distinguish between religious unity in diversity and one uniform religious belief structure. The former I see as possible, even if unlikely, whereas the latter I view as undesirable and impractical.
We need diversity of views, cultures and beliefs. Without "difference", tolerance would be an empty word. Coming into contact with the "other," a person who has a distinct worldview from yourself and looks at an issue from a different vantage point, is for me essential to the concept of freedom. Diversity leads to open-mindedness and prevents people from clinging, in a fundamentalist fashion, to narrow minded views and frameworks that inhibit both personal and societal development.
I do not believe in universal conformity to a single belief system. I do believe in universal cross-cultural consensus on fundamental values and rights, but this comes out of dialogue and negotiation between different civilizations and religions, not the imposition of a single framework of beliefs.
I believe the ideal should be unity in diversity, not uniformity. No
I would not even like Jainism to become the universal uniform religion because out with the moral sphere, it's practices, metaphysical beliefs (which I reject) and so forth emerged out of ancient Indian civilization and are not applicable to the entire human race.
Hence why the Catholic Church, au contraire to its image as a monolithic body, is actually comprised of 24 autonomous 'churches' following distinct cultural practices and theological traditions under the leadership of the Roman Pontiff. Catholicism is not monolithic even though the word Catholic literally means "universal". The universal Church is more like a federation of rites under a strong federal government in the person of the Pope. So while Catholicism is rightly seen as a single, integrated religion - indeed one of the most organised and centralized if not the most - is not a uniform entity.
There are common dogmatic beliefs, values and moral precepts shared by all Catholics, but there are at least 24 ways of being Catholic, hundreds if you consider the different spiritualities of orders like the Franciscans, Dominicans, Carmelites and so forth. One faith in a plurality of rites, traditions, spiritual paths and theological perspectives.
Thus it is not surprising to me that one of history's most lucid and earliest theories of religious unity in diversity, as opposed to uniformity, came from the pen of the Catholic fifteenth century Cardinal Nicholas of Cus. He taught that:
The Word remarks that the variability of opinions is equally entailed in free will.[15] Plurality of opinions is a creation of God, from which we may deduce that freedom of will is not restricted to the capability to sin (as Luther would have it). Plurality is the epitome of human creativity that as much as any undirected potential can go wrong, even if without arbitrary meanness. Otherwise it would be inexplicable why the same freedom is the basis of human sociability...
I think we will always have diversity, even as human beings become ever more integrated through globalization. On one level, this will lead us to smooth over clashes between legal systems and values but on another level it will not override diversity. We will become ever more united while not losing our distinctiveness from each other.
Diversity makes us creative, stimulates independent thought and breeds a spirit of openness. It would be a travesty of colossal significance for the human race to lose or abandon these qualities.