Have you already tried this ...... ??
If you have the Fly spell AND
the Town Portal spell, go up on the roof of the Buccaneer's Lair in New Sorpigal.
You can warp to the Temple of the Gods from there - if you are agile enough !!
[I think this is like some kind of Easter Egg in the game.]
Just make sure you save immediately
you are in a safe place on the roof because you will be attacked the instant you try to reach the Temple.
AND you can't leave the Temple (and LIVE) unless you have Town Portal spell to get you out.
the temple, however, you have access to many valuables - for which you might have to fight, of course