Under the authority of the Divine King, when the decree was issued, transformation ensued.
The 'Fire' Zeus referred to was naturally not just about the flame; in fact, the flame was only an insignificant part of it. It's a term rich in symbolic meaning.
For the flame was a gift to humans from Hestia, one of the deities most friendly towards humans; yet the first act of deception against the gods took place in her temple, and the goddess was not only in charge of [Fire] but also held the divine authority over [Guardianship].
Therefore, the Divine King's decree was in fact severing the relationship between gods and humans, as well as cutting off all divine protection towards them and, conversely, cursing them.
From that moment on, deities would no longer answer the prayers of humans, and all the gifts previously bestowed upon them by the gods were withdrawn one by one.