Shree Krishna to Arjuna; in Bhagvad Gita
Verse 7 Chapter 4
Yada Yada Hi Dharmasya, Glanir Bhavati Bharata
Abhyutthanam adharmasya tadatamanam Srijayamyam
Whenever and wherever there is a decline in Dharma, O descendent of Bharata and a predominant rise of irreligion -- at that time i descend Myself
Verse 8 Chapter 4
To deliver the pious and to annihilate the miscreants, as as well as to reestablish the principles of religion, I myself appear millennium after millennium
Verse 9 Chapter 4
One who knows the transcendental nature of My appearance and activities does not, upon leaving the body, take his birth again in this material world, but attains My eternal abode, O Arjuna
