He was a direct descendant[5] of both Love Brewster, a passenger with his father, mother and brother, Wrestling, aboard the Mayflower and a founder of the town of Bridgewater, Massachusetts; and of Elder William Brewster, the Pilgrim colonist leader and spiritual elder of the Plymouth Colony, and passenger aboard the Mayflower and one of the signers of the Mayflower Compact.

In addition he was a member of the standing committee of the Diocese of Colorado from 1897 to 1906 and examining chaplain from 1900 to 1906.

[10] He was chairman of the joint committee of Bishops and clerical and lay deputies on nominations at the General Convention of the Protestant Episcopal Church, Cincinnati, Ohio, in 1937, and was a commissioner of the World Council of Churches.

[11] In 1936 he presented a resolution to the House of Bishops of the Protestant Episcopal Church requesting Franklin D. Roosevelt to call an international conference of nations which had signed the Kellogg–Briand Pact.

In 1934 he worked in favor of a measure endorsing efforts to obtain for physicians and medical clinics the legal right to disseminate birth control information and the measure passed the House of Bishops by a vote of 44 to 38.

Brewster married on June 10, 1891, in New York City, as his first wife Stella Yates (November 23, 1866 – February 2, 1929),[12] the daughter of Brigadier-General Charles Yates and Josephine Bosworth the daughter of New York Supreme Court Chief Justice Joseph Sollace Bosworth[13][14] and Frances Pumpelly.