Samuel Edger was born probably in 1822 or 1823, at East Grinstead, Sussex, England, the third of eight children of John Edger, a devout Particular Baptist, and his Congregationalist wife, Susannah Ann. Samuel preached from his youth, but his approach even then diverged from the evangelical traditions of his parents. His academic abilities earned him a place at Stepney (later Regent's Park) Baptist College, where his poetic and philosophical approach to doctrine set him apart from other students. He then gained a BA from the University of London, and was appointed co-pastor and subsequently pastor of the Baptist chapel in Bond Street, Birmingham. On 6 October 1846 at Birmingham he married Louisa Harwood. The couple were to have five children.
About 1848 Samuel Edger was appointed pastor of a church of Baptists and Congregationalists without denominational affiliations in Kimbolton, Huntingdonshire, where his liberal views on the church were accepted. Around 1855 he was appointed minister of a chapel in Abingdon, Berkshire. While there he supported the radical nonconformist campaign for disestablishment of the Anglican church, but his rejection of denominationalism eventually led to a dispute with a Baptist trustee and his subsequent resignation.
In 1861 the organisers of the nonconformist settlement at Albertland, north of Auckland, New Zealand, sought a minister for people from several denominations. Edger's non-denominationalism seemed to qualify him, and he was appointed the first pastor. He imagined that the new settlement could reconstruct the shape of the church but the journey out with the first group of emigrants rudely awakened him; his shipboard diary reflects his disappointment at colonists who lacked high ideals. The Edger family and the Albertland settlers arrived at Auckland on 8 September 1862 on the Matilda Wattenbach.
The early years of the settlement were extremely difficult and Edger, who was paid well below the promised stipend, grieved for the lack of an attentive congregation. For their part the settlers did not find Edger's theology congenial, preferring the simple evangelicalism of the local Wesleyan missionary, William Gittos. However, Edger stayed loyal; he established his own farm on a co-operative basis and was the only trustee to fight for the land rights of settlers against the other eight trustees of the Albertland settlement. His greatest pleasure was the building of a small chapel at Te Arai, which was seen as a community chapel rather than a denominational church. For eight months in 1865 he served as temporary pastor at the Albert Street Independent Church, Auckland, while the congregation awaited the arrival of their new pastor, J. T. W. Davies. Edger's preaching appealed to liberal Auckland people, although Baptists were shocked at his willingness to sprinkle infants.
On 5 August 1866 the family house at Albertland was burnt to the ground and all the Edgers' possessions were destroyed. Auckland churches that had got to know Samuel Edger the previous year opened a fund to help the family, and they moved to Parnell. Edger began preaching in the Parnell Hall on 26 August 1866, and formed a church on 9 November 1866. He later moved his activities to the Oddfellows' Hall, then City Hall, and in 1874 to the Lorne Street Hall.
On Sunday evenings, initially at the Choral Hall and later at Lorne Street, Edger gave lectures on popular subjects. Whereas non-denominational congregations were natural in small rural settings, in Auckland the denominations were already well established. Consequently, Edger was treated with suspicion by other clergy, whom he attacked as time-servers, and was excluded from the ministers' monthly meetings. Moreover, theologically he stood with the most liberal of English scholars, in whose writings he was extremely well read. Issues such as the doctrine of the Atonement, conditional immortality, socialism and universalism were all expounded without hesitation, and he harmonised a non-materialistic form of evolution with Christianity. Like a number of liberal Christians he had been alarmed at the growth of materialism. He therefore valued any spiritual emphasis, commenting positively on the writings of Emanuel Swedenborg, and chairing meetings on spiritualism. Edger gathered together a small congregation of like-minded people seeking freedom from any set orthodoxy, and at times services attracted a large attendance. An attack of paralysis in June 1867 forced him to write his sermons in full and read them in the pulpit; this meant that they were swiftly published.
During the 1870s Edger distinguished himself by his advocacy of liberal causes, including the abolition of capital punishment, women's franchise, the abolition of the Contagious Diseases Act 1869, and prohibition without compensation to publicans. He became well known in the community, and served as vice president of the Auckland Choral Society, a member of the Auckland Institute and a member of the committee of the Auckland Society of Arts. He supported a very large number of Protestant causes, notably the Good Templars (for which he edited a weekly newspaper), and he petitioned the Auckland Institute to permit the opening of the museum on Sundays.
Edger's congregation seems to have dwindled in his last years and he suffered from increasing ill health and from the death of his wife on 21 September 1880. In May 1882 he returned to England for surgery, but died in south London on 30 September before the operation.
Edger was an angular person with a long, scrawny beard. He is most often remembered today for his remarkable daughter, Kate, who was the first woman to graduate from a New Zealand university; but he should also be seen as a very influential and individual figure in the intellectual development of Auckland. The impact of freethought in the city was weakened because his behaviour negated many of the criticisms of its adherents, and despite the hostility of other ministers he encouraged some lay Protestants in a liberal approach to Christianity.