The words were written by Louisa M.R. Stead (c. 1850-1917), whose husband died trying to save a boy from drowning. She and her daughter Lily were left destitute. Louisa apparently wrote this song in response to an unexpected provision they received one day.
The tune was composed by William James Kirkpatrick (1838-1921).
YouTube video "'Tis 'So Sweet to Trust in Jesus"
(My apologies as usual if there's an ad before the video.)
More information about Louisa Stead and William Kirkpatrick on the credits page