He was a longstanding editor of the Evangelical Magazine & Missionary Chronicle, author of theological and biographical subjects, and a Congregational pastor at Trevor Chapel, Knightsbridge, London.

He was known for his bold and fervid utterances on the platform, his enthusiastic advocacy of the work of the London Missionary Society, and support for the abolition of slavery in the USA.

[1] Along with fellow London Missionary Society committee member, Thomas Raffles of Liverpool, and his friend the Alexander Fletcher of Finsbury Chapel, he was honoured to be one of the three people to whom the escaped slave Moses Roper brought a letter of introduction on his arrival in Britain, seeking assistance and patronage to pursue his object of promoting the cause of emancipation and abolition.

His style can be seen from this 'Discourse Preached on the Occasion of the Demise of George Fourth' entitled 'God the Setter Up of Kings and Remover of Kings' (1830): Dr Morrison's chapel, Trevor Chapel, was situated at Trevor Square (formerly Arthur Street), Knightsbridge, Kensington, and was demolished in the 1950s after being taken over for use by Harrods department store.

This opened in December 1816, largely paid for by a member of his congregation, John Souter, who bought a lease for the site of chapel, and several houses, in Trevor Square.