State religion
Eardley was raised in the Church of England and despite his subsequent convictions, in particular his condemnation of State religion, remained a member. His beliefs were closely related to Congregationalism, though he never left the Anglican church. In 1839 he became chairman and treasurer of the Evangelical Voluntary Church Association, which campaigned for disestablishment. When the Association was dissolved in 1844, Eardley became chairman of the Anti-Maynooth Committee and Conference which campaigned, without success, against the Maynooth Grant.