Second : You must conquer lust.
Third : You must conquer worldly cravings.
Of these, the second one is most important - conquering lust. Our scriptures say, 'God realization is easy for those who have strictly practiced brahmacharya for twelve years. This is very difficult. I am telling you from my own experience that deep meditation is not possible without practicing brahmacharya. It is a difficult task to control subtle desires.
It is the nature of the mind to enjoy beautiful objects. Unconsciously the mind enjoys many things, and this is harmful to spiritual life. When your life is established in brahmacharya, you will see the manifestation of Divine in everything. By observing Brahmacharya one accumulates OJAS(spiritual energy) in the brain.