Not so long ago, the same chaste Georgian building was a Methodist chapel, and before that a synagogue (Jews, escaping pogroms in Russia and Eastern Europe, settled here in the 19th century; they have moved on since). In 1743, when it set out on its tour of the three great monotheist religions, what is now the Brick Lane mosque was a chapel for the Huguenots, the persecuted French Calvinists who had fled to Britain several decades earlier.
I wonder if God (as the Prince of Wales must surely think) has a special preference for 18th- century English Georgian architecture? After all, He has been happily at home in Spitalfields, the subject of veneration by Jew, Christian and Moslem, for 250 years.
Perhaps, though, the attraction of the former Huguenot chapel is that it has been a comfortable (and affordable) home to the successive rites of Christianity, Judaism and Islam. Could this suggest that, despite the snug fit between Georgian architecture and religion at Spitalfields, the Great Architect, unlike the future Defender of the Faith, has no stylistic preferences? He does seem content to be worshipped by members of different religions in all but identical buildings.
Has the towering and magnificent enterprise of countless generations of architects, masons and craftsmen, the creation of highly distinctive and achingly beautiful mosques, cathedrals, synagogues and chapels, been nothing more than an expensive way of satisfying human vanity?
Perhaps there is no need for a distinct style of religious building for Jew, Christian and Moslem. Perhaps Holy Mass might just as well be celebrated in a redundant underground car- park as in a decorous parish church, and Islamic prayers intoned in an old town hall rather than a purpose-built mosque.
In Bradford, over the past 25 years, mosques have been readily converted from textile mills, houses and cinemas. And, although the Catholic church still enjoys ornament and opulent display, Mass can be as well celebrated in a consecrated Anderson shelter as in Liverpool Cathedral.
But man (and woman), Muslim and Christian, does not live by bread alone - consecrated or otherwise; our lives, both religious and aesthetic, Christian, Jew, Moslem or Hindu, would be very much the poorer if we were to abandon the great art of religious building.
In the plea he made last week for lottery money to be spent on new churches and mosques, Prince Charles was voicing what many of us believe is our increasing need in a sound-bite, superstore culture for places of solace and the spirit. For some people, such a place might be a meditation centre; for others, a church, temple or mosque. The press coverage given to the new Jain temple on the North Circular Road, in Neasden in north-west London, was unprecedented yet understandable. What the Jain community has offered us is the conviction of their beliefs in voluptuous stone and marble.
Liaqat Hussain, a spokesman for the Bradford Council of Mosques, replied to Prince Charles's suggestion, reminding him that "gambling is haram, or forbidden, and it is prohibited to benefit from anything that proceeds from it, so lottery funds could not be used for mosques."
On the other hand, argued Zaki Badawi, chairman of the Imams and Mosques Council of Great Britain, religious leaders might be advised to make an exception to the gambling rule, because "the Prince is striking a very important chord in the heart of minorities who would like to be recognised as mainstream. Although we have discouraged mosques from applying for lottery money," Mr Badawi continued, "we would see this as money coming from the state and would advise communities to accept it."
Zaki Badawi and other Moslem religious leaders are doubtless aware that buildings of high quality tend to raise the profile and standing of religious communities. They also make them friends. The more we are tempted to visit a building because of its beauty, the more we are likely to understand and come to terms with the customs and beliefs of those who built it. This is not a case for giantism, for a new wave of buildings of the scale and ambition of St Peter's, Rome (for St Peter's is more about the power of religious leaders than the strength of their spirituality), but for religious buildings of great quality which will enhance the communities they serve and adorn.
So, although God appears to be content with converted mills in Bradford and plain brick chapels in Spitalfields, he would do well by inspired new religious architecture in Britain; for it is by their architecture that many religions are known. And when faiths vanish, as great religions have in, for example, Peru and Mexico, it is the stones we remember them by. This, of course, is probably anathema to Moslems (and to Jews and Christians, too), who believe that Islam represents the completion and fulfilment of Christianity; the Islamic world is, by its own definition, "the best of all communities". Therefore it cannot and will not fail.
If the Prince's wish was to be be fulfilled and money raised through the Lottery spent on erecting beautiful new churches, temples and mosques in Britain, what should or might they look like? In the case of the Church of England, the answer is that Henry VIII's English hybrid has far too many churches already. The C of E needs to look after its existing fabric before thinking about building yet more. However, even if it were to build anew, how could any architect of any real quality pin down the formal, functional and decorative essence of a Church that appears to believe so many contrary things and no longer has a common book of prayer (or, if it does, has largely abandoned it in favour of customer-oriented facility versions of the original?). A new C of E church might as well look like the Pompidou Centre as Guildford Cathedral. It could be a conference-centre- style meeting hall with a coffee bar and nursery attached, or it could be (not much of a chance, though), an inspiring building designed for procession and prayer.
Does the same apply to mosques? Islam has given the world some of the most exquisite buildings of all: the mosques of central Asia, of Istanbul, Cordoba and Cairo are quite simply stunning. In them, Moslems inevitably prostrate themselves in prayer before the Great Architect; it is not difficult to do in such awe-inspiring surroundings.
In its heyday, this great architecture had an important and direct influence on the development of European Gothic and thus on our finest cathedrals and parish churches. The Gothic style was developed from the pointed arches of Moslem mosques.
Contemporary mosques, noticeably so in Britain, tend to be lacklustre and even banal in comparison with their medieval forebears. The best of the modern British mosques is that at Regent's Park, London. Designed by Frederick Gibberd and Partners, and opened in 1978, it has the virtue of size (big and, with its gold dome, unmissable), but is rather simplistic and, although it works well enough, has none of the proportion, beauty or mystery of its fabulous predecessors.
And, yet, more than many religious buildings, a mosque can be a magnificent thing, not least because Islam places remarkably few constraints on its design.
A mosque is, at heart, a prayer wall. The wall and the faithful who pray before it face Mecca. It is not a place of processional worship and so it need only be the simplest of spaces. If the plan of mosques tends to be square rather than long like a church, this is because the faithful wish to be as close to the wall as possible.
The prayer hall is interrupted only by pulpit and lectern (for readings from the Koran), while outside the building (very often in a courtyard) is a tank and fountain for ritual ablutions; the faithful do not enter a mosque without washing. Minarets, delightful extensions to most mosques, are not essential, but were built higher and higher so that imams could call the faithful to prayer over greater and greater distances as towns and cities spread.
A separate entrance and place to wash is required for women entering a mosque. Inside, a gallery is often provided; the sexes are normally segregated.
The one essential restriction on the designers of mosques is Islam's intolerance towards the depiction of human and animal forms; all decoration must be abstract.
This paucity of rules (there really are very few considering the scope of Islam and the authority and power of its leaders) could allow designers of mosques enormous scope to revive again something of the spirit and aesthetic that created some of the finest buildings of all time.
Perhaps this revival will come as the Islamic community in Britain grows in confidence and ceases to behave - or so it seems to uncomprehending infidels - in a guarded and suspicious fashion. If lottery money comes the way of the poorer Islamic communities (if they will allow it), perhaps we will see buildings to rival Cordoba in years to come.
Of course, any existing building can be converted to serve the rites and purpose of religious communities, but society as a whole would benefit from a new generation of buildings that caused us to join closer together and to pray (in whatever fashion we choose) and allowed God (spirit, the eternal, stillness, a centre - whatever you or He wills) into our chattering, channel-hopping world.