Sri Ramakrishna would advise his devotees to be aware of the illusory nature of worldly existence. He used to narrate a beautiful story to illustrate this idea.
A guru asked his disciple to give up the world and come with him. But the disciple protested, saying that his relatives loved him a lot and that it was not possible for him to give them up. Then the guru said that he will make him understand the reality and gave him a pill. He said that swallowing this pill would make him appear like a corpse externally, but internally he would be conscious and be able to see and hear everything. The disciple went home and lay down on his bed. Soon his external appearance changed and he appeared to have died. His mother, wife and others started weeping bitterly.
Then the guru entered the house and feeling the pulse of the disciple said that he was not dead and that he could be cured by a medicine and restored to life. Hearing this, the relatives were overjoyed. Just then the guru imposed a condition that someone else must take the medicine first and then the boy (his disciple) can swallow the rest. He would be restored to life, but the first person would die. The guru added that since there were so many relatives dear to the boy, one of them would certainly come forward to take the medicine.
At once the weeping stopped and everyone sat there quietly. The wife, who had been crying bitterly a moment before, said that she had young children to be brought up. She asked, who would look after them if she were to die. The disciple saw and heard everything. By that time the effect of the medicine had worn off completely and he sat up and said to the teacher that he had understood the illusory nature of the world. He was ready to go with the teacher.