He considered leaving mainstream Quakerism, as many in his family had done, but in 1840 he attended London Yearly Meeting and decided to remain.

In 1851, Braithwaite married Martha Gillett (1823–1895), also an acknowledged Quaker minister, daughter of banker Joseph Ashby Gillet of Banbury.

In 1869, Braithwaite joined the committee of the British and Foreign Bible Society and made two journeys on its behalf to Eastern Europe in 1882, and to the Ottoman Empire, including Syria and Palestine in 1883.

The Committee arranged for the disownment of David Duncan, the outspoken leader of the Manchester dissidents and published a Declaration of some fundamental principles of Christian Truth, which was, however, rejected by London Yearly Meeting in 1872.

In 1887, Braithwaite travelled to the USA as a British Quaker representative to the Five Years Meeting of Friends in Richmond, Indiana.

[8] This rejection came as a great disappointment to Braithwaite and the Richmond Declaration was one factor leading to the sharp doctrinal turn taken by London Yearly Meeting in 1895, shifting to a more liberal stance and to developing contacts with Hicksite Friends.