Guru leads man to God. Guru, mantra (mystic formula) and devata (deity) form a unity. Guru is present in the mantra which he enlivens and communicates. The mantra is the body of the devata. The guru is the embodiment of the deity that is invoked.
True guru is living God. Devotion to guru trains your heart and prepares for devotion to the Lord. Gurus are plenty but good disciples are very rare. When the disciple is ready the guru appears. He who has a guru can alone know Brahman, and the knowledge received from a teacher alone becomes perfect.
Initiation is necessary to go along the spiritual path. Guru shows you the path. When you are initiated your body and mind become purified. The highest spiritual wisdom experienced by the seers of truth in ancient times, has been passed down to the present day, through an unbroken line of traditional teachers.
Have self-control, tranquillity, sincerity and humility. Then approach the spiritual preceptor. Then alone you will be benefited. Hear silently - anything that your guru may say - hear with faith and bhava. Adapt yourself to his ways. He who serves the preceptor and follows his instructions gains the greatest benefit. He who speaks ill of his guru and does not follow his instructions loses most.
A perfect guru is learned in the scriptures and is desireless. He is a boundless ocean of mercy. He is a full knower of Brahman. He is a friend and a guide to those who have surrendered to him.
Guru is the word. The word is guru. Though God is indescribable, you can see and realise God through the guru.
Here are the characteristics of a real guru. If you find them in any man accept him at once as your guru. A real guru is one who has full knowledge of the self and the vedas. He dispels the doubts of aspirants. He has equal vision and balanced mind. He is free from likes and dislikes, joy and sorrow, egoism, anger, lust, greed, pride, etc. He is an ocean of mercy. In his presence one gets peace and elevation of mind - all doubts are cleared. The guru does not expect anything from anybody. He has an exemplary character. He is full of joy and bliss. He is in search of real aspirants.