The Brattle Street church had been founded in the 1690s by a group of merchants seeking an alternative to the authority exercised by Increase and Cotton Mather in Boston's existing congregations. Despite these beginnings, the church remained Congregational through the 18th century. At the time of the Revolution, Brattle Street counted such figures as John Hancock, Samuel Adams, Joseph Warren, and John and Abigail Adams among its parishioners.
Dr. Samuel Cooper, a graduate of Harvard, headed the church between 1747 and 1783. During the time period addressed in the diary, the congregation left their old wooden meeting house and built a new one of brick. Until services in this new meeting house began in July 1773, the Brattle Street congregation worshipped in conjunction with Boston's First Church.
The writer of this spiritual diary has not been identified, but a half-sheet of paper sewn into the body of the diary indicates that the diarist made a public declaration of faith and joined the church in April 1756.