Approach the entrance and press the confirm button. Go north in the courtyard to enter the main hall.
Talk to the God of Wind, then talk to the other Gods in the main hall.
(If you talk to the God of Fire he'll give you an MP up 25 bit.)
Now go deeper into the temple and talk to the God of Light.
Now go back to the Temple of Space-Time and go to the Future. Exit the temple, and go to the Twilight Settlement.