What goes comes around. If you kill, you will be killed. If you insult, you will be insulted. This is nature's laws. No one can escape. Nothing is happening by chance.A boomerang is a very nice example. If you throw it, it will come back to you at the same speed.

Some say that everything Srila Prabhupada spoke as absolute and blindly apply everything to others, may be not for the self. But if we take a step back and see, we can understand that Prabhupada was very cautious about what he was saying to whom.

For instance, one time Srila Prabhupada wrote a letter to a person saying not to eat avacadoes. But during those days it was customary to publicly read the letters of Prabhupada addressed to anyone by everyone. Later this message spread to everyone and they even stopped offering avacadoes to deities. When this came to Prabhupada's attention, he said it was specific to the person he addressed. 

So while quoting letters of Prabhupada we should be very cautious. Conversations and lectures are different. It takes a lot of intelligence to really apply the right thing at the right time to the right person. 

A doctor who doesn't know the right amount of dosage to the right amount of patient is eventually going to kill the patient than helping him survive. 

The duty of a spiritual master diksha/siksha guru is also similar. If there is over dosage or under dosage the patient will die. Therefore it is essential that there is conversations back and forth between the guru and disciple for better understanding. Blind faith and sentimentalism won't work.