When you wish to begin doing sadhana, first find a guru. Dont try to practise sadhana without a guru. This is particularly true for a householder.
Guru is not just someone from whom you receive a mantra. Guru and disciple work together the way a car and driver always work together. The guru observes every aspect of the disciple how he eats, sleeps, cries, spits, walks. The way a doctor examines a patient, the guru examines the disciple. Until you find such a guru dont go into sadhana. And most certainly, dont try to do it by reading books, or you will go mad.
If you want to practise sadhana on your own, do it after the age of fifty. At this age, the brain starts becoming slower. As one thinks slowly the sadhana is fruitful. But if you practise sadhana at an age when your brain is moving at a superfast speed, your car will fall into a ditch. You cannot drive a car by merely pressing the accelerator. The brakes and the clutch also need to be in order.
The guru is the driver and you are the car. Your steering should be in his hands. Your brakes, the clutch and the speed should be controlled by him. Thats when the sadhana works properly. If by merely practising sadhana from books you could find God, millions would have done it. Many have come and gone, but you hear the names of only a few who attained that. Why? The way there is no husband and wife without marriage, there is no disciple without a guru. A man and a woman can have a relationship without marriage, but a marriage is performed because it is a spiritual necessity. In the same way, a guru is a spiritual necessity. If you start practising japa and pranayama from books without the guidance of a guru, you will find yourself in a mental asylum. We believe:
Guru-Govinda dono khare kaake laagoon paaya,
Balihaaree vaa guru kee jina Govinda diyaa bataaya.
Both guru and God stand before me, at whose feet should I prostrate first,
Glory to the guru who showed me the way to God.
This means that the place of guru is considered higher than that of God. The Shvetashvatara Upanishad (v. 23) tells us:
Yasya deve paraa bhaktih yathaa deve tathaa gurau.
Tasyaite kathitaa hyarthaa prakaashante mahaatmanaha.
Then these supreme truths imparted to the right souls, who are greatly devoted to God as well as to guru, shine brightly. However, they shine brightly only in those souls who are most deserving.
Thus, the one who has abiding faith in the ishta devata and the guru alike attains enlightenment. The kind of bhakti that you have towards God should be towards guru.
The greatness of the guru is held in very high esteem in the Indian tradition. The relationship between guru and disciple is that of the spirit. It is not a limited relationship the way the relationship between father and son, husband and wife, brother and sister, parent and child is limited. The relationship with guru and with God is not limited. The guru is your father, mother, friend, beloved and God. Between guru and disciple, between the devotee and God, there isnt just one relationship, but every relationship. Therefore the guru has been praised in the following words:
Tvameva maataa cha pitaa tvameva; tvameva bandhushcha sakhaa tvameva; Tvameva vidyaa dravinam tvameva; Tvameva sarvam mama devadeva.
You are mother and you are father; You are friend and companion, too; You are knowledge and you are wealth; You are everything, my Lord.
This indicates every form of relationship. That is the belief we hold.