What is the reality of this world, and what does God want from man in it, apart from rituals, and what is the most important thing in existence?

The most important thing is for the servant to know Allah by His names, attributes, and actions. Allah has clarified that this world was created to test creation through His worship, as He Almighty said: "And I did not create the jinn and mankind except to worship Me," and He said: "He who created death and life to test you – which of you is best in deed." The fortunate one is he who is guided to obey Allah, and the wretched one is he who is deprived of that. The obedience of the servant benefits him, and his disobedience harms him. One must beware of delving into questions that raise doubts, because faith in Allah guides the heart.