"The Lord instructs that one has to become fully Krishna conscious to discharge duties as if in a military discipline. Such an injunction may make things a little difficult; nevertheless duties must be carried out, with dependence on Krishna, because that is the constitutional position of the living entity.
The living entity cannot be happy independent of the cooperation of the Supreme Lord because the eternal constitutional position of the living entity is to become subordinate to the desires of the Lord.
His Divine Grace Srila A.C. Bhaktivedanta Swami Prabhupada is not stating this simply for the non-devotees of Krishna lost in material bondage, but also for the devotees of Krishna.
A devotee of Krishna should not avoid practical works in devotional service. Rather, a devotee is always busy in practical services in Krishna Consciousness. A devotee performs even 'ordinary' work in full consciousness of his dependence on the Lord, and in accordance with the instructions of the spiritual master. This is the Yoga of the Supreme Person."
HH Jayapataka SwamiFrom the book: Vrindavane Bhajan Page 69-70