Death, to a good man is but passing through a dark entry, out of one little dusky room of his Father’s house, into another that is fair and large, lightsome and glorious, and divinely entertaining.

Isaac Watts (1674-1748) English theologian and hymnodist

Miscellaneous Thoughts in Prose and Verse [Reliquiæ Juveniles], ch. 32 “Earth, Heaven, and Hell” (1734)
    (Source)

This phrase is often misattributed to Adam Clarke (1762-1832) (e.g., 1853, 1853, 1876, 1880, 1888) or Samuel Clarke (1727-1769) (e.g., 1827). Finding the primary source confirms Watts' authorship, though it is possible that others used the passage in sermons and writings, and the attribution was misremembered.