After his ordination at Lendal Chapel, York, on 1 June 1833, he went to India as an agent of the London Missionary Society. Mather had the pastorate of the Union Chapel, Calcutta, for a few months, then moved to Benares, where he remained until May 1838. He settled at Mirzapur.
There he established a new mission, and in course of time gathered a Christian community, built schools and churches, founded the orphan school press, and started and edited a monthly journal in Hindustani.
Mather returned to England in 1873, after forty years" work in India. At the time of his death, which took place at Torrington Park, Finchley, London, on 21 April 1877, he was engaged on a commentary on the Old Testament in the same language.
She published a Hindustani dictionary of the Bible. After Mather"s death she joined the female mission at Mirzapur, and died 29 March 1879.
Their youngest son, C. B. Mather, went as medical missionary to East Africa.
Their daughter Margaret married Matthew Atmore Sherring.
He preached in the languages of Northern India, and was a member of various associations of missionaries in India. Mather"s wife Elizabeth, née Sewell, had been a church member of Hew Court Chapel, Carey Street, London.