Krishna has made an arrangement for the humans to escape from the clutches of maya, which is, associating with his devotees.
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.
Simply by associating with a pure devotee, one becomes wonderfully advanced in Krishna consciousness. Sadhu-sanga, or association with a devotee, means always engaging in Krishna consciousness by chanting the Hare Krishna mantra but he whose heart is contaminated sees things differently. Therefore by sat-sanga, or association with devotees, one becomes perfectly pure in heart
By glorifying the Lord, we can remain in His association.
Association of people who are striving to be determined helps us to become determined.
By only reading scriptures, without devotee association one becomes an impersonalist.