We have got so many subject matter. We have got Bhagavad-gītā, we have got Śrīmad-Bhāgavatam, we have got Teachings of Lord Caitanya—so many books, hundreds and thousands, Upaniṣads, Veda, Vedānta, any one you select—talk. Just like Ambarīṣa. Sa vai manaḥ kṛṣṇa-padāravindayor vacāṁsi vaikuṇṭha-guṇānuvarṇane (SB 9.4.18). Mahārāja Ambarīṣa, he set a very nice example, that he fixed up his mind on the lotus feet of Kṛṣṇa, and when he was speaking, he was talking about Kṛṣṇa.
So just try to utilize your tongue. It doesn't matter whether it is contaminated or purified, but the process is purificatory. You just train your tongue nicely, engage in Kṛṣṇa. So if you can talk, you go, preach, talk of Kṛṣṇa, talk of Bhagavad-gītā, Śrīmad-Bhāgavatam, lecture anywhere. Then you'll be doing the best service to the people and to yourself. If you think that you are unable to give speeches, then you chant Hare Kṛṣṇa and eat prasādam. So there is no difficulty. So train the tongue. Sevonmukhe hi jihvādau (Bhakti-rasāmṛta-sindhu 1.2.234). Beginning from the tongue, you shall be able to purify all your senses. And as soon as your senses are purified, you'll see Kṛṣṇa, you'll understand what is Kṛṣṇa, what is His name, what is His form, what is His kingdom—everything will be.
Svayam eva sphuraty adaḥ. You haven't got to endeavor. As soon as your senses are purified, Kṛṣṇa is present, just like as soon as the night is over, the sun is present. You cannot search out sun in the darkness. You simply wait for the morning and the sun is at your door. Similarly, try to drive away the darkness, and Kṛṣṇa you'll see. You'll see, "Oh, Kṛṣṇa is not dead. He's so nice."