Sree Sree Guru Gaurangau Jayatah!
Udhava asked Krishna about the great saints following the Vedas, “These are all great saints, and the only source of their teachings are the Vedas, but they all have different advices for attaining the supreme goal.” Krishna asks "Don't you know my teachings? Do you know My view, what I recommend?" Udhava says that yes, in the Gita, Krishna recommends bhakti yoga, devotional service; but not just that, causeless bhakti with no other motivation is His command.
Now what kind of bhakti are we performing? Causeless, with no ulterior motives? No, we will serve for some time, to some degree if there is no obstacles and as long as we are getting some fruit; but as soon as something comes in our way, bauggh. We turn, we abscond. Killing our own guru is even possible. Our service is something like Ravana's.
The demigods were giving Ravana so much trouble in Sri Lanka. He new that Mahadev Siva is the topmost of the demigods. If somehow, he could get Siva in Sri Lanka, all other demigods would give him no more problems. So he knew that Siva is easy to please; you can worship Him with just water and bay leaf. Ravana went to Kailash and started his worship and some intense tapasya. After some time, Siva came to him and was pleased. He offered him any boon that he requested. But Ravana said: "I do not want any boon from you. Please just give me your service. Please come to Sri Lanka so I can worship and please you." With so much bhakti, Ravana was praying, just like a shudha bhakta: I do not want anything but your service.
Then Siva said: "Alright, you can take me in the form of Lingam, which I am non-different from, and worship me in Sri Lanka. But if you set me down anywhere along the way, I will stay there." Ravana got his wish and started the journey. All the demigods now knew that much trouble would start if Ravana made it to Sri Lanka. Somewhere along the way, Varuna, God of the sea entered into Ravana. Ravana suddenly started to feel bloated and an urgent need to pass water. He remembered Siva's instructions about setting Him down, but the pressure was getting unbearable. Finally, he found one Brahmin and asked him to hold Siva Lingam for some time. The Brahmin said that your deity is very heavy; and I may drop him, so no. Eventually, Ravana convinced him to hold Siva Lingam and he went to pass water. As he was doing this, though, he felt no relief. It just kept coming and coming. In the meantime, the deity got too heavy for the Brahmin and he had to set Siva Lingam down. At that time, Varuna left Ravana and he was now relieved, but came to see Siva Lingam placed on the ground.
He prostrated himself several times, with so much bhakti. He was praying to Siva to please come with him, with so much sincerity just like a shudha bhakta. Siva Lingam didn't budge. He tried to lift Him; unsuccessful. Ravana was now very angry: "You won't come? Then there take that," and he hit Him like a boxer. This is what our bhakti is like. If things do not go our way, then there, take that!
Ravana's hit depressed Siva Lingam into the ground. This Lingam can be seen today at Baidyanath in the state of Bihar.
---Jagad-guru His Divine Grace Srila Bhakti Ballabh Tirtha Goswami Maharaj