Transcendental loving service of the Lord begins
Srimad-Bhagavatam
SB Canto 1
When unalloyed practice of sādhana-bhakti is matured into transcendental love for the Lord, the transcendental loving service of the Lord begins gradually developing into nine progressive stages of loving service under the headings of attachment, love, affection, feelings, affinity, adherence, following, ecstasy, and intense feelings of separation
SB 1.7.10, Purport: Unalloyed devotional service of the Lord progresses in different stages. Practice of devotional service in the material field is of eighty-one different qualities, and above such activities is the transcendental practice of devotional service, which is one and is called sādhana-bhakti. When unalloyed practice of sādhana-bhakti is matured into transcendental love for the Lord, the transcendental loving service of the Lord begins gradually developing into nine progressive stages of loving service under the headings of attachment, love, affection, feelings, affinity, adherence, following, ecstasy, and intense feelings of separation.