Śrī Caitanya Mahāprabhu introduced these two things—saṅkīrtana and Śrīmad-Bhāgavatam. And Śrīmad-Bhāgavatam means the expansion of Bhagavad-gītā. Just like in the Bhagavad-gītā you'll find, at the last stage, Kṛṣṇa says, sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66). And Śrīmad-Bhāgavatam also begins from that point. Śrīmad-Bhāgavatam gives introduction, dharmaḥ projjhita-kaitavo 'tra (SB 1.1.2). All cheating type of religious system kicked out, projjhita. Projjhita means just like you sweep over the floor, and all the dust, you throw it away. That is called projjhita. Prakṛṣṭa-rūpeṇa ujjhita.
So this two system . . . one system, to accept the real principles of religion. That is, Kṛṣṇa also explained. It is explained by Kṛṣṇa that Kṛṣṇa came, appeared. Why? What is the purpose of Kṛṣṇa's appearing? Sometimes they argue, atheist class of men, that God cannot come. So why God cannot come? God is your father's servant, that He cannot come? You are ordering? If He cannot come, how He is God? God can do everything. Why you say that God cannot come? He is not under your rules and regulations. Then He is not God. God can come. God says, "Yes, I come!"