Mather was born in Fleetwood, Lancashire, England in 1884, the son of a railway employee and an Irish nurse.
In 1910 Mather sailed to Shanghai, then moved up the Yangtze river to attend the Anqing language school.
Mather was influenced by reading Roland Allen's book, Missionary Methods: St. Paul's or Ours?
Mather was caught up in hostilities in China during the Chinese Civil War, and was accused of political intrigue.
He died on 24 May 1933 of typhus, during the siege of Ürümqi, when caring for people wounded during the Kumul Rebellion led by Ma Zhongying.