What is the use of Advaita in the practical spiritual effort?

Since there is utility in Advaita, it was brought by Shankara into practical spiritual effort (sadhana). Actually Advaita was the situation before creating this universe. After creation of this universe at present there is no Advaita and there will not be Advaita in future. Even in the destruction (Pralaya) there is no Advaita because the entire world is in a subtle state (Avyakta) as a cinema in the film reel. When this subtle state is exposed [manifested], the situation becomes creation. The creation is just like showing the cinema on the screen, which was preserved in the film reel. The Veda says the same (Dhataa Yathapurvam). Advaita means the absence of both the show and the film reel. Therefore Advaita existed once upon a time and it does not exist in the present and will never exist in the future. The producer has created the film after a lot of work. When the film show is stopped the film reel is preserved. Will any fool destroy his own film reel, just to get the situation of Advaita? When you are alive there is no Advaita in this world. Even when you leave the body and go to the upper worlds, there is no Advaita. Therefore Advaita is only an imagination in the present and future. It was a reality only in the past. But Advaita has the practical utility as an intermediate step in your spiritual effort, the aim of which is to please the Lord. During your spiritual effort you will be put through a lot of loss and misery, because you have to sacrifice everything for the sake of the Lord. You need stamina to withstand the loss and misery during such sacrifice. Advaita provides that stamina, because in Advaita, you leave the attachment with your body and you get attached with pure awareness. In such a state you will not be worried by the external factors and you will have ever-lasting peace, which gives infinite mental strength. For this purpose, Shankara brought the concept of Advaita into the practical spiritual effort.