Every spiritual book refers or suggests that "Guru is essential/mandatory for travelling spiritual path". How can we realize and recognize him ? Without him it is not possible to traverse correctly this path. If yes, then how we will find the GURU, who will show us correct path.
Excellent question, Amit. You’re right to think that a guru is necessary if we would know God. The secret to finding the guru is that you must generate the magnetism to be attracted to him or her. You do that through your own deep spiritual sincerity, through yoga practice (especially meditation), through ardent prayer, and by keeping your eyes open for God’s guidance. In short, to attract the guru, you must first cultivate the attitudes and actions of a true disciple.
How can you know what those attitudes and actions are? I suggest you read Paramhansa Yogananda’s Autobiography of a Yogi (especially the chapter “Years in My Master’s Hermitage”) and Swami Kriyananda’s The New Path: My Life with Paramhansa Yogananda, which is virtually a textbook on discipleship. Both books will help you understand the “how” of becoming a disciple. All you need to do then is, do it!
It’s good to search outwardly for the guru as well. However, gurus also have personalities, which sometimes can mask his or her true nature, making it hard to know whether he or she is “yours.” That’s why it is also helpful to look at the disciples of the guru. Considered as a group, their individual personality traits will tend to be “averaged out,” enabling you to get a feeling for whether they have what you want – and hence whether that guru is likely to be “yours.”
You are blessed to have the longing for a guru. I wish you all the best on the all-important quest.