In the Gita, Lord Krishna Himself explains His incarnations:
You and I have passed through many births.
I know them all, but you do not remember.
I am born from time to time
whenever the good need my protection.
I am born to destroy the bad and help the good.
My birth is divine and those who understand this become part of
Me and do not have to be born again.
The Gita, Chapter 4, The Sword of Knowledge, Verses 5-9
These beautifully succinct verse encapsulates Hinduism’s fundamental beliefs: the existence of God, His powers to create and destroy, God’s benevolent intent, the importance of understanding divine power, the reality of reincarnation, and the meaning of salvation which is becoming one with God.
See The Gita, a New Translation of Hindu Sacred Scripture, by Irina Gajjar.
Act Three – Shiva, the Destroyer
Hindu Philosophy understands that the universe appears and disappears in space-time. Its destruction is performed by God. Though essentially unfathomable, Lord Shiva, the Destroyer, represents the human knowledge that existence can be frightening.
The Trinity of Brahma, Vishnu and Shiva embodies a human depiction or explanation of the forces that create, preserve and destroy existence.
Read the the first two acts here:
Act One: Brahma the Creator
Act Two: Vishnu the Preserver
See On Hinduism by Irina Gajjar
From earliest times, Hindus have thought and written about one God called Brahman. Brahman is an all-encompassing truth who has no shape or form but as the essence of Divinity, He flows into many manifestations.
“As Creator of the world, God is called Brahma. As Preserver, God is called Vishnu. As Destroyer, He is named Shiva. These three aspects together form the Trinity, the totality of a single God. From the Trinity, originate God’s thousands and thousands of forms and names.”
from About Hinduism, by Irina Gajjar [to be published soon].