[3] In 1677, before he was twenty, he began to preach, on the advice of Morton and Thomas Manton Next year, in the period of the Popish Plot, a merchant's lecture was begun in the large room of a coffee-house in Exchange Alley.
Four young preachers were chosen as evening lecturers, among them being Shower (with Theophilus Dorrington, Thomas Goodwin the younger and James Lambert).
Twice he moved the congregation to larger meeting-houses, in Jewin Street (1692) and Old Jewry (1701), having successively as assistants Timothy Rogers (1658–1728) and Joseph Bennet.
Shower was a member of a club of ministers which, for some years from 1692, held weekly meetings at the house of Dr. Upton in Warwick Lane, Calamy being the leading spirit.
He published twenty-one single sermons, including funeral sermons for Anne Barnardiston (1682), Richard Walter (1692), Queen Mary (1695), Nathaniel Oldfield (1696), Jane Papillon (1698), Nathaniel Taylor (1702), Nehemiah Grew, and an exhortation at the ordination of Thomas Bradbury; also He married, first, on 24 September 1687, at Utrecht, Elizabeth Falkener (died 1691), niece of Thomas Papillon; secondly, on 29 December 1692, Constance White (died 18 July 1701), by whom three children survived him.