Guru Slokam.

"Gurur Brahma Gurur Vishnu
Gurur Devo Maheshwarah
Gurur Saakshaat Parabrahma
Tasmai Shri Guruve Namah."

Meaning: The Guru is Brahma (The God of Creation).
The Guru is Vishnu (The God of Sustenance).
The Guru is Shiva (The God of Annihilation).
My Salutation to such a Guru, who is verily the Supreme God.