Many of his writings were published by Colney & Schoettle Publishing, during the 1980's and are still under copyright, including the above.
https://www.schoettlepublishing.com/booksonline.htm
See also: GEORGE HENRY LANG - A TRIBUTE By DOUGLAS W. BREALEY.
www.themillennialkingdom.org.uk/WhoWasLang.htm
"The Christian Relation To The State And To War": https://www.themillennialkingdom.org.uk/PerilsOfTheAge/TheCristianRelation.htm