SPIRITUALITY is back, if ever it went away. Sam Harris, one of the leading advocates of the new atheism, published a "guide to spirituality", Waking Up, last year. Then there is Sanderson Jones, co-founder of the highly successful Sunday Assembly, who argues that one of its main tasks is developing a language for spirituality. He describes himself as a "humanist mystic", and feels a "spirit in life" which transcends the everyday.

Now, a proudly secular institution in London, the RSA, has published a long report, Spiritualise: Revitalising spirituality to address 21st century challenges (Leader comment, 2 January). The report argues that spirituality needs to play a greater part in the public realm, because, without it, human beings are unable to draw on the depth in life which is required to tackle seemingly intractable problems, from unfettered consumption to climate change. (The full report is available at http://bit.ly/1AznXRK.).

The author, Jonathan Rowson, consulted widely with more than 300 people of many faiths and none (including, I should add for transparency's sake, me).

This new curiosity about spirituality immediately raises hackles. There is a discomfort with the S- word itself, a feeling that "spirituality" is a vague term (as if "religious" were not). The charge is that it is ethically unengaged, intellectually incoherent, personally embarrassing, sentimental, and passive. One wag consulted by Rowson noted that, when he heard the expression "spiritual but not religious", he described himself as "religious but not spiritual". Last week's affirming Church Times leader still noted that the report did not escape the trap of treating spirituality as a largely individual matter.

The report recognises these difficulties, and makes them a starting- point. Rowson argues that the very vagueness of the term may be an advantage. It is one of those words, like "soul" or "sacred", that don't die, for all the railing against them, because they capture something that is crucial for human beings - crucial, perhaps, for the reason that it can't be precisely captured. The word can, therefore, hold a space that might withstand the onslaught of materialist values, and the tendency to pin down, exploit, and instrumentalise. If no one owns it, no one can claim a monopoly over it.

As for the charge of individualism, I would argue that this is also a strength of the report. Rowson's main motivation for thinking about spirituality is that it is needed to tackle important social issues, by means of personal growth. His professional life in policy development has taught him that, without individual transformation - expressed in the great spiritual injunction to "know thyself" - the big problems stay largely untouched. For Christians, you might say that, unless you and I are prepared to risk the happiness of the poor, the meek, the hungry, and the pure in heart, we may well be actually perpetuating the collective issues that face us.

THE new exploration of spirituality might also help to dissolve the religious barriers that are felt to exclude because they tightly define belief in God or Jesus. Religion itself could come to be seen as "a secure base from which to explore, not a fence beyond which lies infidels", as Elizabeth Oldfield, the director of Theos (and another of those consulted), put it.

Similarly, I wonder whether many religious people are uncomfortable with a serious, transformative spirituality, because of the demands it would make on them as individuals. Church of England religiosity currently seems to be taking a highly extraverted and paradoxically this-worldly turn. It is energised by a concern for the socially excluded and materially marginalised, as no doubt it should be. But such matters can also serve to keep the challenge of Christianity safely in other people's lives, thereby sidestepping the question whether we ourselves are dying each day to live more in Christ.

Related to the personal issue, spirituality should be a mission issue too. After all, if the mood music about spirituality has changed, it is also clearly true that a majority of people have not stopped believing in God or that there is a spiritual dimension to life. What has changed is the sense that the Church of England has much to offer when it comes to exploring those depths. As the Bishop of London, the Rt Revd Richard Chartres, recently put it in an interview with the philosopher Jules Evans: "The real trouble with the Church is not that it has retrograde social attitudes. . . It's that it's spiritually incredible."

For all the valuable campaigning on issues of social justice, if the Church does not know and communicate the feeling that life is rooted in a source deeper and more compelling than the everyday, then it has lost touch with its wellspring, and its days will look increasingly numbered. The RSA report - and the new interest in spiritual depth - is, I believe, implictly a challenge to us, and to our Church.

Mark Vernon is a psychotherapist and writer in London. He also teaches at The Idler Academy.