Positive dialogue and active social outreach between different religions is a much-needed ideal in our world today. On this prospect, advocates of various religions have spoken with great enthusiasm for many years. They have exhorted their respective communities to study widely the teachings of other religions with an open mind, to not insist that one's own religion is superior to other religions out of a misguided notion of loyalty, nor even to assume that followers of other religions need to convert to one's own religion for their own benefit. All this is sound advice, but preliminary advice at most. Even if perfectly adhered to, is such advice alone sufficient to engender fellowship between different religious communities? Likewise, can mere public gathering of representatives of many religions, but whose interaction is limited to superficial conversation, be expected to bring about lasting rapport?
I am fundamentally optimistic about the potential for interreligious solidarity, but I also believe that it will only come about when it is pursued on all sides as a well-defined objective. A social relationship of any kind is only as rewarding as the commitment that each party is willing to invest into it in the first place. We must decide whether we are content with interreligious solidarity as a vague, nice-sounding idea that ever remains as an idea, or whether we consider it important enough to invest into it the same kind of intellectual structure that we would invest into any other practical project as a matter of course. If the latter, then I would like to explore how this process might begin.
Sincere solidarity, by definition, is built upon common purpose. Two or more parties without a common purpose can be polite towards one another, but will never really view each other as fellows, never be ready to make sacrifices for one another - which has always been the most reliable test of solidarity, whether between individuals, organizations or even countries. As such, whether or not solidarity between religions is possible depends on whether or not a common purpose can be identified.
To this I add two caveats. Firstly, common purpose must be distinguished from common interests. Common interests refer to the pragmatic, such as receiving funding or publicity. Two or more parties which band together so that all can profit is not solidarity, but merely alliance of convenience. Remove the incentive of profit, and with it so goes the alliance. Common purpose refers to the ideal, such as promoting a certain spiritual attitude. Only two or more parties which know they are all striving to steer hearts and minds towards the same general direction can express genuine solidarity. Secondly, identifying a common purpose must be distinguished from contriving a common purpose. The common purpose must be intrinsic to the original content of the religions, not a diplomatic creation, or else the solidarity will not only be false, but also likely to derail the original content of the religions themselves in the bargain.
Writing to a Buddhist readership, I will examine the issue of common purpose from a Buddhist starting point. The purpose of Buddhism is universal transcendence of samsara. This would imply that solidarity can only be sought with other religions which are universal in concern and which have transcendence as their aim.
By universal, I mean religions which welcome all who wish to join it, as opposed to those which intend membership by only a limited group. Buddhism itself is very much universal: the Buddha stated explicitly on many occasions that all sentient beings possess Buddha-nature and can attain Buddhahood, and was an outspoken critic of the Vedic caste system which divided society into hierarchical strata according to ancestral descent. Other religions with which Buddhism can express solidarity must therefore also be open to all, and not founded on any kind of clannishness, ancestralism or ethnocentrism.
By transcendent, I mean religions whose goals are set beyond this present existence, as opposed to those concerned with worldly benefits. Buddhism exemplifies the mentality of transcendence: the first of the Four Noble Truths is the truth of dukkha which permeates all of samsara, thereby asserting the ultimate futility of material ends. Other religions with which Buddhism can express solidarity must therefore also set their goals in the beyond.
While a number of religions satisfy both these conditions, the most famous religions which satisfy both our conditions would be Christianity and Islam, which along with Buddhism are known as the three great supercultural religions in the world today. Like the Buddha, both Jesus and Muhammad aimed at salvation for everyone, and taught spiritual detachment from this world. The three religions also share contextual similarities, such as founding by a single teacher who was considered by his contemporaries as anti-traditional and revolutionary, and the ability to appeal to societies across a diverse range of cultures. It is even arguable that they underwent similar processes of degeneration over the ages since the death of their founders.
So how might expression of solidarity between such religions meaningfully proceed? I suggest it would be necessary for a discussion to occur regarding the special strengths of other religions that may be absent in one's own. However, this must be a discussion between religions, not within them. If such a discussion occurs only within religions, it could easily deteriorate to a scenario in which each religion attempts to plagiarize the special strengths of the others and adapt them for application within its own system, leading to rivalry - a kind of spiritual arms race - instead of solidarity. What I propose is the opposite of this: a discussion between religions where each other's special strengths are openly recognized as such, which can lead to ideas for division of labour towards the common purpose. For example, Buddhism tends to appeal to atheists rather than theists. Instead of trying to broaden its appeal to theists by compromising its own content, it could simply encourage theists to consider Christianity or Islam. The reverse would also apply.
Religions with a common purpose but differing strengths need to start seeing themselves as distinctly specialized forces with the same mission, like the navy, army and air service of a military campaign. Each has its optimal niche of contribution within the mission, and each needs to recruit according to its specialities. A navy has no reason to incorporate army or air service exercises into its own training. If a navy comes across a recruit prone to seasickness, it would not hesitate to recommend him for enlistment in the army or air service instead, rather than stubbornly keep him in the navy. Thus the navy maintains its own special strengths, and also communicates trust for its fellow forces via willingness to divide labour.
On the other hand, trust can only be built on respectability. A navy would be perfectly justified in distrusting a supposed fellow army if the army displayed a lack of basic discipline and ethics that the navy demands for itself. The same surely applies to religions. Therefore, in contrast to the counterproductivity of trying to adopt each other's strengths, it is crucial that each religion eliminates from itself what could be perceived as weaknesses by other religions with which solidarity is sought. Each religious community must raise its own standards so as to beget the confidence of other religious communities. To be driven to excel by the aspirations of others is a reliable sign that one views these others as friends and comrades. Until such a state is reached between religions with a common purpose, until each religion is motivated to improving itself not for the sake of competing with the others but for the sake of not letting down the esteem of the others, interreligious solidarity has yet to truly succeed.