 As a Member of Parliament Barnewall was required under the "Act of Supremacy (Ireland) 1560" to acknowledge Elizabeth I as head of the Church of Ireland.This was an advantageous step since his family had benefitted greatly from the suppression of the religious houses, and, whatever their private religious beliefs, they clearly had no wish to lose any of the former monastic lands which they had acquired.Christopher's own private sympathies were undoubtedly with the Catholic faith, which his son Patrick in later years openly championed.