Gerhard Gerhardsson was born in Fällfors, Byske parish, Västerbotten, Sweden, to farmer Gerdt Nilsson and Cathrina Andersdotter.
A booklet made him concerned, which had recently been published and was circulating in the area, entitled Allvarlig förmaning till alla rättsinniga kristna att vakta sig för falsk lärdom men i synnerhet för Per Tollessons skrifter ('Serious admonition to all right-minded Christians to beware of false doctrine, but especially of the writings of Per Tollesson').
On New Year's Eve, he underwent a dramatic spiritual experience lasting nine days in which he read the Bible and believed he was alternately in heaven and hell.
He disagreed in part with Lutheran theologian Johann Arndt's True Christianity, ending in a dispute with two local priests.
Despite his lack of official schooling, Gerhardsson brought a statement of faith he had written expounding on the New Readers' beliefs, consisting of 22 articles on 24 pages, based on the format of the Augsburg Confession.
On 9 January 1822, King Charles XIV John decreed that the provisions of the Conventicle Act were no longer to apply to the Readers there.
His son, the later influential preacher Carl Olof Rosenius, met Gerhardsson at some point and spoke to him about spiritual matters.
Schartau too had been a strong proponent of Moravian beliefs but later broke with the group and their focus on sentimentality as he found a more intellectual version of faith.
Around this time, in opposition to the state church separatist New Reader Johan Riström [sv] had amassed followers and founded his own congregation in which he held mass, heard confessions, and confirmed and baptized children.
Carl Olof Rosenius would later lament Gerhardsson's turn towards Schartauism in a letter to Finnish priest Fredrik Gabriel Hedberg.