„Oh no, this Mataji is also here! Why is that Prabhu joining our group? I don’t like that fellow.“ We might sometimes feel like that, and it’s probably not possible to be friends with everyone. However, we should be careful, for it is said that to not become joyful upon seeing a Vaishnava can be considered a Vaishnava aparadha!
Vaishnava aparadha is compared to a mad elephant: „when a mad elephant enters a nice garden, it spoils the entire garden. Similarly, if one becomes like a mad elephant and commits offenses at the lotus feet of a Vaishnava, his entire spiritual career is halted. One should, therefore, be very careful not to commit offenses at the lotus feet of a Vaishnava.“ 1
The Skanda Purana lists different kinds of offenses against a devotee of the Lord. Killing a Vaishnava is an offense, that's pretty obvious. Indra had to do penance at Mansa Sarovar for a thousand years to become freed from his offense after he killed Vritrasura. To blaspheme a Vaishnava is another aparadha. Daksa offended Lord Shiva in this way and had to suffer the consequences. To be envious like Gopala Capala (towards Srivasa Thakur) or to become angry with a Vaishnava, like Saubhara Muni who became disturbed by Garuda, is also considered to be an offense. Indra failed to show respect to his Guru Brhaspati and lost all his power because of that. As mentioned in the beginning, even to not feel joyful upon seeing a Vaishnava is another form of aparadha. This shows how careful we should deal with and feel respect for each other.
I remember how I had a hard time with a particular devotee at the temple. I really did not like the guy and tried to avoid his association. Actually, he was a good devotee, but his mood was just so different from mine. One day, while walking in the city, all of a sudden, I saw that same devotee on the other side of the street. Very spontaneously I raised my arms and called out „Haribol Prabhu!“ and felt so happy to see a devotee of Krishna in the midst of all these people who do not show any interest in spiritual life. „Wait a minute,“ I told to myself. „Why do I feel so much joy seeing that devotee, I thought I don`t like him?“ At this moment I realized how silly it was to maintain such enmity toward that Prabhu, after all, he is a devotee of the Lord.
There is a very instructive story in regard to offending a devotee by not becoming joyful upon seeing him:
One day in Vrindavana, Srila Rupa Goswami sat rapt in meditation and felt great bliss in his heart. While sitting in his samadhi he observed a wonderful pastime. The Gopis were decorating Srimati Radharani while Krishna stood behind Her watching. Krishna revealed His presence to the sakhis, but Radharani was unaware that He was there. In many ways, the Gopis braided and decorated Radharani’s hair and then they placed a mirror before Her. As She gazed at the beauty of Her own face, Radharani also saw Krishna's moonlike face in the mirror. Radha became very shy and quickly covered Herself with Her clothes. The Gopis happily laughed at this and Srila Rupa Goswami also joined their laughter.
Just at that moment, a Vaishnava arrived who was very eager to see Rupa Goswami. Seeing Rupa Goswami laughing, the Vaishnava did not say anything, but feeling sorrowful in his heart he went away. (This Devotee named Krishnadas was lame and unable to walk properly and he thought that Rupa Goswami was laughing at his disability). After that incident, Srila Rupa Goswami suddenly lost his vision of the Lord's pastimes and began looking everywhere. Considering the situation very carefully, he concluded that someone must have come to see him while he was absorbed. He thought “Because I did not honor the person who came, I thereby committed an offense.”
After both of them, Krishnadas and Rupa Goswami, came to see Sanatana Goswami the misunderstanding was cleared and both Vaishnavas begged for forgiveness from each other. Srila Narahari Chakravarti concludes the story by saying: „ Although Srila Rupa Goswami is a highly elevated devotee very dear to Sri Caitanya Mahaprabhu, the Lord used him to teach us the danger of Vaishnava aparadha. (..) Be careful not to see a Vaishnava’s fault, and always sing their glories“. 2
1 - Srimad Bhagavatam 6.17.15, Purport
2 - Sri Krishna Kathamrita No.6 - Vaishnava Aparadha, page 19
From Srila Narahari Chakravarti`s Sri Bhakti-ratnakara, fifth wave