[1][3] On 26 December 1861, he married Mary Anne, eldest daughter of N Brice, at Dinapore Cantonment while he was based in Monghyr (Munger, Bihar).
He also organized regular meetings at the Soldiers' Institute in nearby cantonment town of Landour and at the Woodstock School there.
[17] In 1894, Gregson visited South Africa during a time when Andrew Murray, Keswick and Higher Life leader, was ministering there.
It was during this particular meeting at Lanouli camp, where Pandita Ramabai, the famous Indian social reformer (who had already become a Christian in 1887), experienced a deep spiritual awakening and professed to have been touched by the Holy Spirit.
[18] After this meeting, she and her friend together had a conversation with Gregson where she asked several questions which he answered based on the Biblical Scripture much to the satisfaction of Ramabai.
[14] Gregson held many talks and classes with the priests and laymen within the Mar Thoma Church, after obtaining approval from the Malankara Metropolitan.
[14] Although Gregson had to leave, as an indirect result of his mission work, in 1897, the vicar of Kumbanad and Eraviperoor Mar Thoma Churches, P E Mammen (Kumbanattachen), received baptism from Handley Bird,[24] a Brethren missionary, at Kunnamkulam.
[20][22] Eventually, his ministry led to the establishment of Brethren movement, supported by Volbrecht Nagel who celebrated the Holy Supper on 19 March 1899 at Kunnamkulam.