Spontaneous loving service to the Lord is called devotional service with an intimate attachment between the servitor and the served. This intimacy is called mamatā. Between the servitor and the served there is a feeling of oneness. This mamatā begins with dāsya-prema, service rendered to the master by the servant. Unless there is such a relationship, the loving affairs between the Lord and His devotee are not actually fixed. When the devotee feels “The Lord is my master” and renders service unto Him, Kṛṣṇa consciousness is awakened. This fixed consciousness is on a higher platform than simple cognizance of love of Godhead.
Ref >> Srila Prabhupada Vani.