The godfather of the movement was John Frederick Maurice, the son of a Unitarian who became an Anglican priest and brilliant academic. Maurice was a Broad Churchman, and was sometimes subjected to investigations of his supposedly over-heterodox theology, but he did not go along with the more extreme kinds of German liberalism. Instead, Maurice devoted himself to improving the education of the poorer classes, setting up colleges for women and for working men. He helped to inspire the establishment of the Christian Social Union, established in 1889 with Brooke Foss Westcott, a leading Biblical scholar, as its president.
The social Gospel movement proper, however, is often seen to have started with Walter Rauschenbusch, who despite the name was not German but American. Raised in a traditional Baptist family, Rauschenbusch found his faith shaken when he went to college and learned of higher criticism. He became deeply influenced by liberal theology, especially its emphasis on the kingdom of God as a human society based on love. He felt that Christians needed to recover this emphasis in the teaching of the Bible, which had become obscured by an obsession with the salvation of the individual soul after death. This was translated into a concern for real action after he worked as a minister in New York City’s notorious Hell’s Kitchen area in the 1890s.
In his "Christianity and the social crisis", Rauschenbusch insisted that
no man shares his life with God whose religion does not flow out, naturally and without effort, into all relations of his life and reconstructs everything that it touches. Whoever uncouples the religious and the social life has not understood Jesus. Whoever sets any bounds for the reconstructive power of the religious life over the social relations and institutions of men, to that extent denies the faith of the Master.
Views such as these were highly influential, not only within Christianity but within wider society. Progressive politicians such as Woodrow Wilson were deeply influenced by Rauschenbusch, and so too were later Christian leaders in the vanguard of social reform, such as Martin Luther King and Desmond Tutu. Such views were even more prominent in Canada, where they spread throughout the theological colleges. One of the most important figures was Salem Bland, a Methodist minister who possessed enormous charisma and (it was said) the eyes of a prophet. Bland, based at Wesley College, helped to organise those with social Gospel views into a powerful lobby group within the church. He was also a popular speaker in his own right and spread these views throughout Canada.
In Britain, meanwhile, ideas like these were a major influence on the nascent labour movement. James Keir Hardie, a Scottish union leader, founded the Labour Party in 1900 to promote what would become known as socialist values. Hardie, a vocal campaigner for women’s rights, Indian home rule, and other progressive causes in the early twentieth century, had been raised as an atheist but converted to Christianity and became a lay preacher. His socialism was based in large part upon his Christian convictions, which not only fed into his concern for social justice but led him to steer the Labour Party away from out-and-out Marxism. In "From serfdom to socialism", written in 1907 while Labour leader, Hardie wrote:
This generation has grown up ignorant of the fact that socialism is as old as the human race... When the old civilizations were putrefying, the still small voice of Jesus the Communist stole over the earth like a soft refreshing breeze carrying healing wherever it went.