Jesus - teacher of the moral law

In the 1860's following the revelations of geology and evolution Matthew Arnold imagined the 'sea of Faith' as a tide: But now I only hear its melancholy long withdrawing roar retreating... down the vast edges drear and naked shingles of the world. (Dover Beach) Now in the 21st century that retreat in the West has reached the point that half the population has abandoned Christianity the rituals and creeds of which have ceased to have meaning in a Post-Enlightenment age. Yet in Western Europe Christianity at its best defined our civilisation with its accompanying morality art music and architecture inspiring such movements as the anti-slavery campaign the compassionate treatment of the insane and a myriad of charities for the sick and deprived. This morality came directly from the teaching of Jesus of Nazareth encapsulated in the so-called Sermon on the Mount.