was elected a fellow of Emmanuel College, Cambridge, but, declining to take the oath of allegiance to George I, lost his fellowship. Edward Gibbon made him the tutor of his son, the father of the historian Gibbon, in c.1727, and he remained as an honoured friend of the family in their Putney home until 1740, when he became the centre of a small spiritual community at King's Cliffe (his birthplace) near Stamford.
He is chiefly remembered for his treatises of practical morality, A Practical Treatise on Christian Perfection (1726), and more particularly A Serious Call to a Devout and Holy Life (1728). This work is addressed to believers, and urges them to a simple and pious way of life, with emphasis on private rather than public prayer; it is enlivened with many satiric character portraits. This work greatly influenced Dr Johnson and Law's friend J. Wesley. (See also Byrom for Other Aspects of his Personality.)
In later life Law became increasingly interested in mysticism and in the writings of Boehme; some critics have seen in The Spirit of Prayer (1749–50) and The Spirit of Love (1752–4) a foreshadowing of Blake's attacks on materialism and reason.