Once Sri Caitanya Mahaprabhu was asked to define who is a Vaishnava, a devotee of the Lord. Caitanya Mahaprabhu’s answer was: asat-sanga-tyaga,—ei vaishnava-acara - A Vaisnava is someone who gives up the association with non-devotees. 1 Also Narada Muni advises in his Narada Bhakti Sutras: dushangam sarvathaiva tyajyah - One should give up all kinds of degrading association 2. The same instruction we also find in Srila Rupa Goswami’s Upadesamita. Why do the acaryas give so much emphasize on this? Because association very much influences our consciousness. This is explained in Hari Bhakti Suddhoya as follows: „Association is very important. It acts just like a crystal stone, which will reflect anything put before it.“ If you put a lotus flower before a crystal stone you will see the beauty of that lotus reflected in that crystal. But if you place dirt in front of the same crystal the same dirt will be seen. Whatever association we choose to have will have a strong impact on our consciousness, therefore one should be careful with whom one associates with. Thus, good association is very helpful, whereas bad association can harm us.
Once Srila Prabhupada learned that some of his initiated disciples had indulged in their formal habits of smoking marijuana. Prabhupada said this was due to bad association, and he gave the example of bedbugs. During winter, bedbugs seem to disappear from your bed, but in due time they emerge and again bite you and grow fat on your blood. Similarly, a transcendentalist`s kama, lust may seem to be entirely subdued but it is actually present in a very reduced state. If given fresh opportunity, his material desire will strike again. 3 So, therefore, all bad association should be given up. But how to do that in one’s daily life? And what does association actually mean?
Srila Bhaktivinoda Thakur explains that if just by coming close to a materialist or a material object is considered association with them, then there is no way to give up such association. So that's not possible. But what we can do is be careful to whom we give our heart to, because it is the engagement of the heart, or in other words the feeling of affection and love that defines if we actually associate with someone or not. Therefore Bhaktivinoda Thakur discriminates between dealings out of duty and dealings of true love.
The following story gives us a better understanding of this principle: Once there was a monkey named Red Mouth, he lived on a great fig tree and very much enjoyed its fruits. This monkey developed a friendship with a crocodile named Terrible Teeth. For many days they ate fruits together and talked about life and its meaning. One day the wife of the crocodile came to know about their friendship and told her husband: “This monkey friend of yours must have a heart made of nectar, as he eats nectar-like fruits all the time. Please bring me that heart.” Forced to prove his love to his wife Terrible Teeth had no other alternative than to do what was needed. The next day he invited his monkey friend to ride on his back. The foolish monkey jumped down from the tree and soon found himself clinging onto the crocodile’s back in the middle of the river. Red Teeth asked the crocodile: „Where are we going? “ The crocodile replied: „ I`m going to take you home, where my wife will cut out your heart and eat it for lunch!“ Red mouth immediately called out: „ Why did you not tell me this earlier? I indeed have a nectarine heart, but it is my second heart that I always keep on the tree. Don`t you know that we monkey keep their second heart in trees? Let's go back to get it. “ Terrible Teeth thought that this was a good proposal and allowed the monkey to touch shore. Red Mouth jumped back into his tree and refused to accept further invitations from the crocodile. The moral of the story: You may associate with materialist, but don`t give them your heart. 4
Of course, as devotees of Krishna we certainly should learn to respect, appreciate and eventually love everyone, understanding how we all are related to Krishna. But as sadhakas, spiritual practitioners, while trying to become free from the influence of the illusory energy, we need to be careful to whom we give our hearts, to whom we reveal our minds or in other words to whom we develop deep friendship, because association acts just like a crystal stone.
1 - Cc.Madhya 22.87
2 - Narada Bhakti Sutra, Sutra 43 (NBS)
3 - This paragraph is taken from the Purport of NBS Sutra 45
4 - Pancha Tantra / Purport of NBS Sutra 45