He was himself the author of several volumes of sermons which were published during his lifetime.
He wrote Practical Sermons (1858; edited by Noah Porter); Lectures on the Moral Government of God (2 vols., 1859), and Essays and Lectures upon Select Topics in Revealed Theology (1859), all published posthumously.
The sermons of Flechier increased his reputation, which was afterwards raised to the highest pitch by his funeral orations.
He was specially devoted to the Virgin Mary, and wrote an Officium Beatae Virginis, in addition to many letters, sermons, and other writings.
The fact that standards of Methodist doctrine are laid down as consisting of "Mr Wesley's Notes on the New Testament and the 1st Series of his Sermons" (fiftythree in number), might seem to indicate a departure from existing systems, but it was not so.