Voysey was sacked from the curacy of St Mark's, Whitechapel, having denied the doctrine of eternal punishment. He then became curate of Healaugh, Yorkshire, but soon ran into difficulties there. He was prosecuted by William Thomson, Archbishop of York, for heresy, starting in 1869. The Judicial Committee of the Privy Council gave their judgement in 1871:
The Appellant is charged with having offended against the Laws Ecclesiastical by writing and publishing within the diocese of London certain sermons or essays, collected together in parts and volumes, the whole being designated by the title of "The Sling and the Stone," in which he is alleged to have maintained and promulgated doctrines contrary and repugnant to or inconsistent with the Articles of Religion and Formularies of the Church of England.
His appeal against this conviction was dismissed and Voysey lost his benefice. He went to London and founded the Theistic Church of London.