The root cause of devotional service to Lord Krishna is association with advanced devotees. Even when one's dormant love for Krishna awakens, association with devotees is still most essential.
Only one who is fortunate can have the opportunity to hear Srimad Bhagavatam in the association of pure devotees of the Lord.
If one wants to acquire the mercy of the Lord, he has to associate with pure devotees. Such association alone can, by degrees, release one from the quivering elements.
Great unalloyed devotees of the Lord are compassionate towards the fallen and therefore they travel all over the world with the mission of bringing souls back to Godhead, back to home. Such pure devotees of the Lord carry the message of Godhead in order to deliver the fallen souls and therefore the common man who is bewildered by the influence of the external energy of the Lord should avail himself of their association.
Love of God is awakened by the association of pure devotees of the Lord.
If one is in good association he can develop the mode of goodness and if in bad association he may develop the mode of darkness or ignorance.