After he graduated from Cambridge, he travelled round the world twice (he became an accomplished horseman and crack shot) and he discovered a vocation to the priesthood - although no satisfactory explanation seems to have been found for what sparked off his interest in Ritualism. He was ordained deacon in 1863 to a title at St Mary-the-Less, Lambeth, but he spent only a year there, because his churchmanship clashed with that of his vicar. He was ordained priest in 1864 and served a second curacy at St Mary's, Folkestone. From 1865-68 he was minister of St Mary Magdalene's mission church in the parish of St Nicholas, Chiswick. In 1868 he became vicar of St James's, Hatcham, a working class parish in south-east London.
Tooth's efforts to renew the life of St. James', Hatcham, started to attract large congregations. His approach combined capable preaching, the introduction of ritualist practices, and the establishment of parish organisations designed to help the more needy residents of the area. He also established the Guild of All Souls at St. Jame's in 1873.
When the Public Worship Regulation Act was passed in 1874, those who disapproved of his ritualist liturgical practices set a prosecution in motion. He was charged with (among other things) the use of incense, vestments, and altar candles. The case came before Lord Penzance at Lambeth Palace on 13 July 1876. Tooth did not attend as he refused to recognise the authority of the court. He ignored both the judicial warnings that resulted from his non-attendance and the legal attempts to restrain him from exercising his ministry, although he was now facing disruptions when he presided at worship caused largely by people hired for the purpose by his opponents.
Eventually, on 22 January 1877, as a result of his repeatedly ignoring the decisions of the Court of Arches, he was taken into custody for contempt of court and imprisoned at London's Horsemonger Lane Gaol. This action immediately transformed him in the eyes of Anglo-Catholics from a rebel into a Christian martyr, and his story became national headline news.
The agitations that resulted from his arrest and imprisonment played a central role in bringing the Public Worship Regulation Act into disrepute. His conviction was quashed on a technicality.