Through the association of devotees, one can engage in the service of the Lord by hearing and chanting. Thus one can revive his dormant Krishna consciousness and sticking to the cultivation of Krishna consciousness, return home, back to Godhead, even in this life.
The most essential point of avoiding bad association is to give up the bad association of one's materialistic mentality.
As we associate with others in our spiritiual communities, we should do so in a mood that these are the people that I am living with and they will probably also be the people that I will leave this body with.
What is the association of devotees? It does not mean that being around with people with tilak and shaved heads or with saris. It means engaging in the nine processes of bhakti (devotional service) together.
Association can make us convinced about anything.
Faith comes by hearing Krishna Katha in the association of sincere devotees regularly.