His maternal uncle was Robert Seddon, who (after receiving Presbyterian ordination on 14 June 1654) became minister at Gorton, Lancashire and Langley, Derbyshire, where he was silenced in 1662.
It does not appear that Bourn accepted this view; his theology was always Calvinistic and, although he regretted deflectors from that system, he was no hunter of heretics.
In 1679 Samuel Annesley's influence gained him the pastoral charge of the Presbyterian congregation at Calne, Wiltshire (which he held for 16 years, declining overtures from Bath, Durham and Lincoln.
On his deathbed, in answer to his friend Jeremiah Aldred (d. 1729, minister of Manton) he emphatically expressed his satisfaction with the nonconformist position he had adopted.
A portrait prefixed to the volume shows a strong countenance; Bourn wears gown and bands, and his flowing hair is confined by a skullcap.