Day always follows night. The two are perfectly correlated. Therefore, night causes day ?

No, night does not cause day. The statement that day always follows night and the correlation between the two does not imply causation. Day and night are natural phenomena that occur due to the rotation of the Earth on its axis and its position relative to the Sun. Daytime occurs when a particular location on Earth is facing towards the Sun, while nighttime occurs when that location is facing away from the Sun. The sequence of day and night is a result of these natural processes and not caused by one another.