Bhagavad Gita 6.14प्रशान्तात्मा विगतभीर्ब्रह्मचारिव्रते स्थितः।मनः संयम्य मच्चित्तो युक्त आसीत मत्परः ॥

The spiritual aspirant should possess serenity of mind. The Divine Light can descend only in a serene mind. Serenity is attained by the eradication of Vasanas or desires and cravings. He should be fearless. This is the most important qualification. A timid man or a coward is very far from Selfrealisation.A Brahmachari (celibate) should serve his Guru or the spiritual preceptor wholeheartedly and should live on alms. This also constitutes the BrahmachariVrata. The aspirant should control the modifications of the mind. He should be balanced in pleasure and pain, heat and cold, honour and dishonour. He should ever think of the Lord and take Him as the Supreme Goal.Brahmacharya also means continence. Semen or the vital fluid tones the nerves and the brain, and energises the whole system. That Brahmachari who has preserved this vital force by the vow,of celibacy and sublimated it into Ojas Sakti or radiant spiritual power can practise steady meditation for a long period. Only he can ascend the ladder of Yoga. Without Brahmacharya or celibacy not an iota or spiritual progress is possible. Continence is the very foundation on which the superstructure of meditation and Samadhi can be built up. Many persons waste this vital energy -- a great spiritual treasure indeed -- when they become blind and lose their power of reason under sexual excitement