If we read the Vedic literature, and you get full knowledge, and the essence of Vedic literature is Śrīmad-Bhāgavatam. And the Bhagavad-gītā is the preliminary study of Śrīmad-Bhāgavatam, A-B-C-D. This Bhagavad-gītā is the A-B-C-D of knowledge. This is entrance examination, matriculation examination, school-leaving examination. And Śrīmad-Bhāgavata is graduate. When you become graduate in spiritual knowledge, then you can understand Śrīmad-Bhāgavatam. And when you have passed your Bachelor degree, when you are postgraduate, that study is Śrī-Caitanya-caritāmṛta.
So we have got three different status of reading capacity. We have got already twenty books. So don't waste your time. Try to understand what is Kṛṣṇa and what is spiritual life by reading these books. Everything is explained there. Don't associate with this material nature. If you associate with this material nature, then what will be the result? Now, kāraṇaṁ guṇa-saṅgo 'sya sad-asad-yoni-janmasu (BG 13.22). Yoni means the source of birth. Just like we take our birth, the source is the mother. From the mother's womb we come out. That is called yoni, the source. The source is the mother. From the mother's womb we come out. That is called yoni, the source. So there are mothers—human being mother, cat mother, dog mother, this mother, so many mothers. Without mother there is no birth. And without father also, there is no birth. Therefore it is said that janame janame saba pitā mātā pāya. In every birth you will get a father and mother, because without father and mother there is no question of birth.
So here also see, sad-asad-yoni-janmasu. Why one is being born through the mother of a cat or through the mother of dog or a human being or a king or a demigod? The mother, through mother you have to come out. That is called yoni. But why these different mothers? Kāraṇaṁ guṇa-saṅgo 'sya. As he has infected the eighty-one qualities, colorful qualities of this material nature, the nature will give you a suitable body through the particular mother.