A guru or spiritual master is a teacher of traditional subjects of Vedanta, Sanskrit and other classical Indian studies. In order for these to be taught, the guru needs to be in communion with his Soul, so that this knowledge can be communicated to the student appropriately. The guru therefore needs to be a spiritual master.

Today, however, there are no gurus in the world and hence it is not possible for anyone to progress far along spiritual lines unless through the help of God.

According to Indian tradition, one's parents are one's first gurus and they have a responsibility to teach you spiritual and religious knowledge. At the age of seven or eight, when the parents' ability to impart spiritual wisdom had been exhausted, the child was sent to an ashram to learn all the sciences, arts and philosophies needed by him/her and particularly to gain spiritual wisdom from, and serve, the Ashram guru: what might be called a true rather than parental guru.

It should be stated that the ancient scriptures describe guru as being God. This is because one needs to respect one's teacher.

For religious progress, you need simply to wish to love and serve God

For some realistic comments on 'gurus' Andrew Cohen, BKS Iyengar, Tibetan Zen Buddhist Sogyal Rinpoche, Baba Hari Dass, and various others, you need to search the web. A place to start is http://www.flameout.org/flameout/gurus/index.html#godmen.