[2] The first evidence that he functioned as a non-conformist preacher is from the year 1665 at the time of the Great Plague of London.

In 1672 his congregation built a large meeting house for him near London at Rotherhithe, where it is said that he had a very numerous auditory, and a great reformation was wrought amongst many.

[5]It became an effective evangelistic tool, and was the most widely read book in nurseries in England next to the Bible and Pilgrim's Progress by John Bunyan.

He was among the signers of the 1673 Puritan Preface to the Scottish Metrical Psalms and contributed one of the "Cripplegate Sermons: Duties of Masters and Servants".

Charles Haddon Spurgeon referred to Janeway's works in his sermons on many occasions in the late 1800s.