The human body is rarely achieved and although temporary like other bodies, it is meaningful because in human life one can perform devotional service. Even a slight amount of sincere devotional service can give one complete perfection.
One who acts to serve Krishna with his body, mind, intelligence and words is a liberated soul, even within this material world.
Devotional service is dependent on the mercy of Krishna and His Devotees. Unless we surrender to the lotus feet of a pure devotee, it is not possible to come to the platform of pure devotional service. By his own efforts a bee cannot taste the honey within a bottle. The bottle must be opened by a superior. If the bee simply licks the outside of the bottle, thinking "Now I am tasting honey," Then he is in illusion. Similarly, no one can enter into devotional service unless the door is opened by a devotee.
Always remember why you have joined ashrama or ISKCON. The real purpose of doing so is to be engaged in devotional service.
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.
Krishna does not agree to award devotional service to merely anyone. Krishna can easily offer a person material happiness or even liberation, but He does not agree very easily to award a person engagement in his devotional service. Devotional service can in fact be attained only through the mercy of a pure devotee. — The Nectar of Devotion, Page 14.