Sri Ramakrishna would often try to impress upon his devotees the supremely unreal or impermanent nature of the world. To illustrate this point he used to narrate incidents from Ramayana.
Sri Ramachandra had been exiled for 14 years to live a life of austerity in a forest. Sri Laxmana and Sita had voluntarily accompanied him. One day, one of the rakshashas of Ravana by the name of Maricha disguised his real form and appeared as a golden deer. To fulfil Sita’s desire, Sri Ramachandra started chasing it and was taken to quite a distance. Laxmana also left the kutia (small hut) at the bidding of Sita. In the meanwhile, Ravana came and took away Sita to Lanka. Rama and Laxmana wanted to go there to rescue her. But they had to cross the ocean, which was obstructing their journey to Lanka. Suddenly, Laxmana became angry and taking his bow and arrow he said that he would kill Varuna, since the ocean was preventing their going to Lanka. Sri Rama calmed him and explained the matter saying that all that Laxmana was witnessing was unreal, i.e. like a dream. The ocean and Laxmana’s anger were unreal and that it was equally unreal to think of destroying something unreal by means of another. Sri Rama was God incarnate on earth and by his mere wish he could have destroyed Ravana and brought back Sita in a trice. But he was aware of the entire lila that he had to enact on earth in his avatar as Rama. He willingly participated in it so as to teach mankind.
Thus Sri Ramakrishna would say that one should constantly be aware of the unreal or impermanent nature of the world as contrasted with the eternal nature of God. Taking the world too seriously would obscure a sadhaka‘s vision and take him away from the path of righteousness. This would hinder sadhana as well as progress in the path of spiritual enlightenment.