One who acts to serve Krishna with his body, mind, intelligence and words is a liberated soul, even within this material world.
Meditation means stopping all nonsensical activities, at least for the time being. Devotional service, however, not only puts an end to all nonsensical mundane activities, but also engages one in meaningful devotional activities. — The Nectar of instruction, Text 02
The Kingdom of Godhead is not a myth but it is situated far beyond the boundary of the material cosmos and one can know it by the process of devotional service only.
Devotional Service should start at early age, and not during old age.
By rendering devotional service unto the Personality of Godhead, Sri Krishna, one immediately acquires causeless knowledge and detachment from the world. — Srimad Bhagavatam, 01.02.07.