First birth is from your parents, but real birth, real life, begins when one accepts a bona fide spiritual master and renders service unto him. Then the path is open for going back to home, back to Godhead, to live eternally in full knowledge and full bliss and in association with the Supreme Personality of Godhead Himself, Lord Krishna.
A. C. Bhaktivedanta Swami PrabhupadaTherefore a person fully absorbed in the bodily concept of life is surely killing himself by not making spiritual progress. Such a person is called pasu-ghna. Especially excluded from spiritual life are the animal hunters, who are not interested in hearing and chanting the holy name of the Lord. Such hunters are always unhappy, both in this life and in the next. It is therefore said that a hunter should neither die nor live because for such persons both living and dying are troublesome.
A. C. Bhaktivedanta Swami PrabhupadaOut of many millions of wandering living entities, one who is very fortunate gets an opportunity to associate with a bonafide spiritual master by the grace of Krishna. By the mercy of both Krishna and the spiritual masters, such a person receives the seed of the creeper of devotional service.
A. C. Bhaktivedanta Swami PrabhupadaIn spiritual life, one must conduct one's whole life under the guidance of the guru. Only one who executes his spiritual life under the direction of the spiritual master can achieve the mercy of Krishna.
A. C. Bhaktivedanta Swami Prabhupada