Vanisource:Sloka of the day/September 23, 2008
ete cāṁśa-kalāḥ puṁsaḥ
kṛṣṇas tu bhagavān svayam
indrāri-vyākulaṁ lokaṁ
mṛḍayanti yuge yuge
All of the above-mentioned incarnations are either plenary portions or portions of the plenary portions of the Lord, but Lord Śrī Kṛṣṇa is the original Personality of Godhead. All of them appear on planets whenever there is a disturbance created by the atheists. The Lord incarnates to protect the theists.