Educated at Ruthin grammar school and St David's College, Lampeter (then affiliated with Oxford University), Roberts graduated in 1878.

By year's end, Roberts had sailed to Nassau, Bahamas, where he was ordained a priest and made chaplain of St. Matthew's Anglican Church.

He met Bishop John Spalding of Wyoming and Colorado, and asked for missionary work in the diocese's most difficult field.

[3] However, Bishop Spalding wanted the young priest to first gain experience, and so sent him first to tend to the spiritual needs of coal miners in Greeley, Colorado, and then to the mixed community in Pueblo.

With that experience, Roberts secured his dream job in 1883, ministering to the Shoshone and Arapahoe tribes and other people within 150 miles of Fort Washakie.