Guru Purnima is celebrated on the full moon (purnima) of Ashadh.
It is also known as Vyas Purnima as it is the birthday of Bhagwan Ved Vyas.
Vyas Muni is the Adi (original) Guru of the Hindu as He classified the Vedas, wrote 18 Purans and the Mahabharata.
Gurus are acknowledged and worshipped on this day.
In Sanskrit ‘Gu' means darkness or ignorance and ‘Ru' means remover hence Guru = the remover of ignorance/ darkness.
Only the one who removes us from Maya (ultimate darkness) and inspires us to follow the path of God realisation is a true Guru.
On Guru Purnima, disciples offer pujan and reverence to the Guru in mind, action and speech; they obey his unvoiced wishes, commands, serving him as one would God and lauding his glory and redemptive attributes.
A spiritual aspirant, no matter how brilliant, can never attain such knowledge by his own endeavour. This is stipulated in the Shrimad Bhagvatam in which Jadbharat reveals to king Rahugan: "O Rahugan! One cannot attain knowledge of Atma and Paramatma by performing penance, sacrifices, renunciation, Vedic study or worshipping deities of water, fire or the sun. But when the dust from the feet of a sat-purush (God-realized Guru) sprinkles on our heads, then we can surely attain this knowledge."
Gurubrahma Guruvishnu Gururdevo Maheshwaraha | Guruhu sakshaat Parambrahm tasmai Shrigurave namaha ||
"The guru is Brahma, Vishnu and Mahesh (Shiva), veneration to the Guru who is Parabrahm manifest."
This does not literally mean that the Guru becomes Parabrahman - God, rather he is venerated as if God He is manifesting through him.
Guru Govind donu khade, kisko laagu paay, Balihari Gurudevaki jinhe Govind diyo bataay.
The Guru and Govind -God, are present before me, to whom shall I bow down first? Glory to the Guru since he showed me Govind.
Bhagwan Swaminarayan too considers the Guru as foremost; to be venerated as one venerates God.
Gadhada Antyam Prakran 27th Vachanamrut: "The scriptures advocate five attributes of: Nishkam, Nirlobh, Nirman, Niswad and Nisneha for a sadhu. The sadhu in whom one observes such attributes has a constant rapport with God. Therefore one should have immutable faith in his words, and by his words should realise the knowledge of God."
Gadhada Antyam Prakran 26th Vachanamrut: "The sadhu who lives in a way in which he subdues his indriyas and antahkaran, but is not subdued by them, who engages in God-related activities only, strictly observes the Panch Vartamans, believes himself as being Brahm and worships Lord Purushottam, can be known neither as a human being nor a Deva, since neither man nor Deva possess such attributes. Therefore such a sadhu, though a human being, deserves to be worshipped at par with God."
In this era it is very difficult to find such Gurus, especially as many rogues disguise themselves as sadhus. However, it is in our best interest to find the right one; this can be done by sitting with saints and denoting the best Guru for you.
You should not be in a rush to find a spiritual Guru; rather it should be a well researched and thought through decision.
Teachers at school are also our Gurus, so we must offer them as much respect as we do to sadhus. To curse, insult them or do their ninda in any way would ultimately be an insult to Lord Swaminarayan.
There are 2 highest forms of charity in this world; 1) Aan Daan (food charity); and 2) Vidya Daan (Giving of knowledge). We should appreciate the fact that someone wishes to gives us knowledge.
Maharaj has also said that we should impart what knowledge we have onto others; to keep it to yourself would be greedy and selfish.