What do modern people lack, spiritually?
Some people have the experience of yearning for something which the world cannot give - for example when enjoying music, or a story, or a landscape - we may feel a joy which is also a yearning, since we know the world cannot satisfy it - indeed that we ourselves are unable to sustain it.
Either such moments are a meaningless delusion, or they mean something - and that something feels very important.
Christianity explains such moments and feelings as a foretaste or glimpse of Heaven.
The moments are meant to be an inspiration and encouragement - these moments ought not be sought for themselves, certainly these moments should not be grabbed or held onto; yet they are moments which with the right attitude are good for us, indeed potentially very good for us indeed - this is Christian mysticism, the via positiva - the worldly path to transcendence.
Christian evangelism and apologetics usually ignores this - instead focusing on morals and logic. But the yearning triggered by beauty is another way-in.
Yet Christian worship usually seems almost entirely to neglect this! Where, in the Christian life, are such moments of yearning encouraged?
This is not a matter of cheerful and enjoyable music, but of sublime music; not a matter of comfortable churches but beautiful churches (beauty which may be the glory of a cathedral or the plain austere beauty of a Quaker meeting house like Brigflatts).
And the words - the words ought not be merely true or sincere or interesting or relevant or funny - but poetic. Pointing beyond themselves. How dare we neglect that!
Imagine someone who feels this other worldly yearning going to church - what will they find? Will this yearning be encouraged and taken up into its full meaning; or will the church be irrelevant to yearning?
Church ought not be merely friendly, or at least friendliness is not enough - neither is happiness enough (there is plenty of modern friendliness, and even happiness, we can get happy friendliness at a fast food outlet) - but each and every formal act of Christian worship should itself be hinting or pointing at transcendence. Neither is good advice nor solid teaching enough; and certainly good works are not enough.
Modern souls cry-out for a Heaven-glimpsing beauty which is especially deficient in modern life since modern life is so comfortable, so full of varied distractions and instant pleasures.
Yearning for the unattainable, the unworldly, is not confined to Christians - but Christianity has the capability of not just explaining but doing something with this transcendent yearning.
Christian worship, Christian life ought - surely - to encourage transcendent Heaven-glimpsing experience if at all possible?
Christian evangelism should be able to encourage those who are experience this yearning, to take their search into the Christian church, in expectation that this feeling will be channeled and nurtured.
Note: The above argument is based on CS Lewis's writing on Joy/ Sehnsucht and JRR Tolkien's essay On Fairy Stories.