They emphasized the Millennium and the Second Coming of Christ and believed, among other things, that the soul was mortal, that Jesus was God (and not being Trinitarian that when he died there was no God in heaven, Moses and Elijah looking after heaven until the resurrection), that Heaven was six miles above earth, that God was between five and six feet tall and, like the Quakers, that any external religious ceremony was not necessary. Some scholars think Muggletonian doctrine may have influenced the work of the artist and poet William Blake.
The Muggletonians had a belief that they could damn and bless according to the will of God and the apparent success of such damning (apparently resulting in the death of certain religious, mainly Quaker, opponents) brought the sect great prestige. A vigorous tract war ensued with their Quaker opponents that lasted until the death of Muggleton.
During the nineteenth century this formerly non-proselytizing Protestant sect became increasingly vocal and published several books intended for general audiences. In 1846, for example, the Muggletonian Isaac Frost published Two Systems of Astronomy, a lavishly illustrated book outlining the anti-Newtonian cosmology of the Muggletonians. This activity arose from the activity of the Frost brothers (Joseph and Isaac) who having made their fortune in the Derby Brass Foundry business proceeded to spend significant sums on publicising their sect once the family moved to London. A great quantity of books were published but very few were actually sold.
The group survived up to the twentieth century. The last Muggletonian, Phillip Noakes of Matfield, Kent, died on 26 February 1979; the sect's records, which he had kept, were then transferred to the British Library.The published works of the Muggletonian Brethren are still available from Gage Postal Books of Westcliffe-on-Sea, Essex.