Chosen disciples are fully transformed by Guru to become perfect; such remaking can be very painful, but still is the highest mercy

Neem Karoli Baba and Dada Mukherji

 (from "The near and the dear" by Dada Mukherji"):

Many persons have felt that Babaji's [Neem Karoli Baba's] methods of making and remaking the lives of his devotees were often very hard and sometimes appeared to lack mercy, This, of course, was not true. The whole basis of his work was nothing but mercy, kripa, for the helpless and forsaken ones. He knows where, when, and how such mercy is to be used in the job. A murti may be made from clay, wood, or stone. The work of the clay modeler is done with soft and delicate touches of his hand. When it comes to the sculptor working with stone, he has to take up the chisel and hammer. They are both merciful in their jobs, but mercy has to work in different ways. Babaji knew this very well; we can see it in his work in different places and with different materials.

Emptying and cleaning are considered essential in the making of a vessel suitable for holding sacred water. The processes differ from one another according to the state of the vessel. One might be comparatively clean, and soft and simple methods will be enough. Hard treatment is necessary when the vessel had been used for well or pond water and sediments had been deposited; impurities have turned into crusts and clots. The impurities have to be taken out to make the vessel worthy of the sacred water. The task is not simple. Babaji knew it and did it with full consciousness. The cost of the unavoidable surgical operation had to be paid in pain.

The spiritual transformation elevation of the closest devotees of Baba might have seemed unusual to their relatives and friends [with whom were living totally mundane life before meeting Baba]. But it would not have seemed unusual to those who had seen many such cases before. Those who saw or knew the murtis only, but not the craftsman, saw each as distinct and separate from the other. But for those who had met the craftsman from whose murtis came, and had seen him at work, they were not distinct. All the murtis were the products of the same master hand. The unique underlying qualities could not be traced by judging one or two of them at random, but when you took them as a whole, you could find the missing link. 

The predominant thing was that everyone was perfect and complete in itself. This remark does not refer to all and sundry who came to Baba for darshan but only for special treatment. Their number is small, as far as we know. So thus there is no major difference in nature between such elect disciples when they come out of the master's craftsman's workshop. They were first emptied of all unwarranted and spurious things and then cleaned and purified. These processes are different for each, but when complete, each newly filled vessel is filled with the sacred water. Between such kripa-patras (recipients of grace) there is a unity in their separation - the unity of separate flowers in the same garland. The flowers were different, but the florist was the same for all of them.