People may question that "Lord Buddha is accepted as an incarnation of Lord Kṛṣṇa." Keśava dhṛta-buddha-śarīra jaya jagadīśa hare. "Then why he preached atheistic philosophy?" He preached, "There is no God." Śūnyavāda. But there was necessity at that time. Why? That is explained by Jayadeva Gosvāmī:
- nindasi yajña-vidher ahaha śruti-jātaṁ
- sadaya-hṛdaya darśita-paśu-ghātam
- keśava dhṛta-buddha-śarīra jaya jagadīśa hare
At that time, people were killing animals like anything in the name of yajña. In the Vedas there are prescriptions that in the yajña a paśu can be, an animal can be slaughtered. In some yajña, not all. Tāmasika-yajña.
Anyway, Vedic injunction is there. So when Lord Buddha started this nonviolence, ahiṁsā paramo dharmaḥ, the Vedic scholars approached him that "How you can prescribe this ahiṁsā? There is already sanction in the Vedas, paśavo vadhāya sṛṣṭāḥ... How you can stop it?" So Lord Buddha said, "I don't care for your Vedas." Therefore he is considered as atheist. Anyone who doesn't care for Vedas, they are technically called as atheist. Veda nā māniyā bauddha haila nāstika. Nāstika means atheist.