William Wilberforce (1759 – 1833) was an English politician, philanthropist and a leader of the movement to abolish the slave trade. Born in Kingston upon Hull, he went on to become independent MP for Yorkshire (1784–1812). Converted in 1785 he soon made major life changes and began a lifelong concern for reform. In 1787 he met Thomas Clarkson and other abolitionists who persuaded him to take on the cause. He soon became a leading English abolitionist, heading the parliamentary campaign against the British slave trade 26 years until the final passing of the Slave Trade Act, 1807. He also championed things such as the Society for the suppressionn of vice, missionary work in India, the creation of a free colony in Sierra Leone, the foundation of the CMS and the (later R)SPCA. He later supported the campaign to completely abolish slavery from outside Parliament. Abolition throughout the Empire became certain just three days before his death. More here.
Bonhoeffer uses a similar phrase 'worldly Christianity'. It's J Gresham Machen that I want to line up most closely with. See his Christianity and culture here. Having done commentaries on Proverbs (Heavenly Wisdom) and Song of Songs (Heavenly Love), a matching title for Ecclesiastes would be Heavenly Worldliness. For my stance on worldliness, see 3 posts here.