He graduated from Andover Seminary in September 1827 and, while waiting a specific charge, organized a Sunday school and stood for ordination in Brandon, Vermont.

They traveled to Honolulu by March 30, 1828, on the Parthian, as part of the third company from the American Board of Commissioners for Foreign Missions.

He was an early member of the Royal Hawaiian Agricultural Society, founding a local chapter and published reports of his progress growing wheat and other non-tropical crops at higher elevations.

[8] In 1844 he published a biography of an early convert who was known as "Blind Bartimeus", after the biblical character, born with the Hawaiian name Puaaiki.

[9] At the suggestion of local chief Kiha, he founded the independent Poʻokela Church in Makawao on land donated by King Kamehameha III, conducting services in the Hawaiian language.

He took a trip back to the mainland, and then married Asenath Cargill Spring (1820–1894) from Providence, Rhode Island, in 1863.

[14] His son Joseph Porter Green was born October 30, 1833, served at the church, and was elected to the legislature of the Hawaiian Kingdom in 1860.