Baba discoursed on the Sadguru:
Without the sanskaras being totally eliminated there is no spiritual liberation. To dispose of sanskaras one has to create "reverse" sanskaras, which are opposite in nature. Opposite impressions reverse the sanskaric makeup of the mind. To remove stains, soap or lime is necessary. But the mind never dies of itself.
For example, suppose your hand is to be broken. It is difficult and almost impossible for you to twist your own hand enough to break it. But if a sturdy fellow comes along and twists it, your hand fractures in a second. That sturdy chap is the Sadguru who is required to deal with the mind and all its mischief.
But a Sadguru is not to be found so easily. It requires love, the search for Truth amidst hardships and sufferings, and undergoing untold difficulties — these draw the Sadguru to the deserving ones.
If by hurting a person temporarily you provide a permanent healing, this apparently cruel act of yours is, in fact, a blessing. In the same way, suppose that by rendering a temporary healing you create a permanent hurt; this apparently blessed act of yours is, in fact, a curse. A doctor cutting open a boil and causing so much pain to the sufferer is considered an enemy who has hurt one; but when the pus is removed the patient is relieved, and the doctor is considered a real friend who helped.
So the Sadguru is at first apparently considered an enemy when he tries to remove sins and wipe out desires and sanskaras of the aspirant by forcing strict discipline on him, renunciation, et cetera. But when the bliss of union with the Divine Beloved is attained through his grace, he is considered a true friend.
To come into contact of a Master (Avatar or Sadguru) requires preparation of many past lives. Action of a Master may appear adverse and pain giving but ultimately results in spiritual benefit.