On this holy occasion of Guru Purnima, Pujya Bhaishri explains why we refer to our Guru as Brahma, Vishnu and Mahesh from the popular shloka:
Gurur Brahma Gurur Vishnu Gururdevo Maheshvarah,
Gurur sākshāt Parabrahma tasmai Shri Gurave namah
Guru is Brahma, Guru is Vishnu, Guru is Shiv; Guru is Supreme God. Guru is God present in front of our eyes.
So, why is Guru Brahma? We know Lord Brahma is the creator. Similarly, a Guru creates humanity in a person. Merely having the body of a human does not mean one is humane. We have to learn to be humane. Can we call it a chilli if it is not hot? Can we call it sugar if it is not sweet? Likewise, can we call a person a human if one is not humane?
Thus, a Guru creates a true disciple just like Lord Brahma creates. Just like Lord Vishnu protects, a Guru looks after his/her disciple. A Guru enhances the good qualities within a disciple and protects these good qualities. Just like Lord Shiv destroys, a Guru destroys the vices within a disciple. Hence, a Guru is Brahma, Vishnu and Mahesh.
When one has the thirst and desire to know and experience and God, God worries and arranges his devotee to meet a suitable Sadguru. God Himself presents as His devotee’s Guru. Therefore, Guru is Supreme God.
On this occasion, let us devote our self to our Guru and please him by chanting the shloka once again:
Gurur Brahma Gurur Vishnu Gururdevo Maheshvarah,
Gurur sākshāt Parabrahma tasmai Shri Gurave namah