This book, written by Founder of The Salvation Army William Booth, began in 1900 as a series of letters concerning the blessing of a clean heart to be read in weekly gatherings of Salvationists. The teaching of the blessing of a clean heart was, and is, a central tenet of Salvationism, reflecting the Movement's Methodist roots.

Purity of Heart 2016, Createspace Independent Publishing Platform

ISBN-13: 9781534643758

Trade paperback

Purity of Heart 2007, Salvation Army, London

ISBN-13: 9780854127665

New edition