Thakura Bhaktivinoda was not official Spiritual Master of Gaura Kisora dasa Babaji Maharaja. Gaura Kisora dasa Babaji Maharaja was already renounced order, Paramahamsa, but Thakura Bhaktivinoda, while He was even playing the part of a householder, was treated by Gaura Kisora dasa Babaji Maharaja as Preceptor, on account of His highly elevated spiritual understanding, and thus He was always treating Him as His Spiritual Master. The Spiritual Master is divided into two parts; namely, siksa guru and diksa guru. So officially Bhaktivinoda Thakura was like siksa guru of Gaura Kisora das Babaji Maharaja. (Srila Prabhupada Letter to Dayananda, 1 May 1969)