Love and Devotion
If one offers Me with love and devotion a leaf, a flower, fruit or water, I will accept it.
Bhagavad Gita 9.26
Symptom of A Pure Devotee
This is the symptom of a pure devotee. One should serve the spiritual master first. It is not that one should bypass the spiritual master and desire to serve the Supreme Lord. This is not the principle for a Vaishnava.
Mind
For the one who has conquered the mind, the mind is the best of friends; but for one who has failed to do so, his very mind will be his greatest enemy.
Chanting The Hare Krishna Mahamantra
Chanting the Hare Krishna mahamantra, vanquishes all the effects of sinful activities.