The necessity of positive duty, or actual goodness : A sermon preach'd in the Parish-Church of St. Sepulchre, June the 5th, 1718. Being Thursday in Whitson-Week; at the anniversary meeting of the children educated in the charity-schools in and about the cities of London and Westminster. By William Lupton, D.D. preacher to the Honourable Society of Lincolns Inn, and prebendary of Durham. Publish'd at the request of several of the gentlemen concerned in that charity.