Roberts spent his entire career as a practicing physician in East Asia, dying in China after seven years of mission work.

His parents were devout Christians, and Roberts was exposed to prayer and Bible lessons from a young age.

[1] In the months following his graduation from medical school, Roberts applied to serve with the London Missionary Society.

From Shanghai, Roberts' group traveled north by land to the London Missionary Society settlement in Tientsin.

[7] When Dr. Mackenzie left the mission to treat patients in the countryside for several weeks, Roberts was put in charge of teaching surgery to the Chinese medical students.

Roberts and Gilmour traveled between the London Missionary Society's three missions in the Mongolian countryside, remaining at each one for a few days.

Roberts was then asked by the London Missionary Society to return to Tientsin to take over operations of the mission hospital.

Following Mackenzie's death, Viceroy Li withdrew government support of the Tientsin hospital, which led to many of the workers leaving.

Seeking to increase missionary work among the local women, he wrote to his sister Mary asking her to join him.

All of Roberts' medical services were free of charge, and he would use his salary from the London Missionary Society to support the hospital's expenses.

[2] In addition to his treatment and evangelism efforts, Roberts also collected data on dysentery for a thesis he was preparing and was active in the Medical Missionary Association of China.

Thomas Bryson traveled to affected villages after the floods to provide the people with money to sustain themselves through the cold season.

After the arrival of Dr. Smith in 1892, Roberts and his sister travelled 100 miles southwest to the villages of the Yen Shan district to provide medical care and evangelize among the people.

[10] Roberts' writing lives on through his contributions to the memoirs of his former colleagues, John Kenneth Mackenzie, Medical Missionary to China and The Story of James Gilmour.