Who can become a Bona fide Guru ?
Srila Prabhupada...."Guru is the cloud or he is the agent of drying water from the ocean of mercy of Kṛṣṇa and turn it into a mercy cloud and pour water on the saṁsāra dāvānala, and then it is extinguished. Saṁsāra dāvānala-līḍha-loka-trāṇāya kāruṇya-ghanāghanatvam, prāptasya kalyāṇa **
Therefore guru must be authorized person, not that bhūmi-phala-guru(?). No. "I am guru," no. You cannot become guru unless you are agent to draw out the mercy water from the ocean of mercy of Kṛṣṇa. That is guru. And therefore a guru is not an ordinary person. He is the representative, bona fide representative of Kṛṣṇa. Bhaktivinoda Ṭhākura has sung, kṛṣṇa se tomāra, kṛṣṇa dite pāra: "Vaiṣṇava Ṭhākura, Kṛṣṇa is your property. If you like, you can give." Vedeṣu durlabhaṁ adurlabhaṁ ātma-bhaktau[Bs. 5.33].
You cannot get Kṛṣṇa by studying Vedas. That is not possible. There is Kṛṣṇa in the Vedas, but you cannot pick up. It is not possible. But if you go to the Kṛṣṇa's favorite person... Kintu prabhor yaḥ priyaeva tasya. Kṛṣṇa's very dear servant, confidential servant, is guru. Nobody can become guru unless he is in confidence of Kṛṣṇa. Na ca tasmād manuṣyeṣu kaścid me priya-kṛttamaḥ. These things are there. Not that by magic one can become guru. No.
Srimad-Bhagavatam 5.6.8 -- Vrndavana, November 30, 1976