Sri Chinmoy: To be very frank with you, the necessity of a living Guru in order to realise God is not absolutely indispensable. The first person who realised God on earth, the very first realised soul had no human Guru. The poor fellow who first realised God had only God as his Guru.
If you have a Guru, what happens? It facilitates your inner spiritual progress. A Guru is a private tutor. At every moment in life’s journey, ignorance tries to test you, examine you and torture you, but this private tutor will teach you how to pass the examination. If you have a private tutor you know how much help you can get in order to pass the examination. Moreover, if you get a Guru, once you get him and once you are in his boat, he takes you to the Golden Shore. You on your part do not have to work as hard as you would have done without a Guru.
The Guru is approached by his disciple at any time, any hour of the day or night, in his suffering, in his joy. The necessity of a Guru for a sincere disciple is certainly of paramount importance. But at the same time, it is not indispensable. However if someone is wise enough to want to run towards his Goal instead of stumbling or merely walking, then certainly the help of the Guru at that time is considerable.
Again a true disciple feels that the Guru and the disciple are not two totally different beings; that is to say, he does not feel that the Guru is at the top of the tree and he is at the foot of the tree, that he is all the time washing the feet of the Guru. No, he feels that the Guru is his own highest part. If he has the feet, he has also the head. He feels that he and the Guru are one, the Guru is his own highest and most developed part. Therefore he does not find any difficulty in surrendering his lowest part to his highest part. It is not beneath his dignity to offer his lowest to his highest because he knows that both the highest and the lowest are his.
So to come back to your question, the need for a teacher. It is absurd to feel that for everything else in life we need a teacher but not for God-realisation. But again, God is in everybody and if you feel that you don’t need human help, you are most welcome to do it alone. But why does one go to the university when he can study at home? He need not go to university, but he feels that there he will get expert instruction. In this world, if you want to make fast, faster and fastest progress in the inner life, spiritual life, then I must say that the necessity of a Guru is almost indispensable.