In their eyes, the gods were omnipotent, and when they spoke of matters related to the gods, the gods could hear them.
Gaven, of course, couldn't tell them that the gods were not so omnipotent, that they could hear them just by calling their names a few times. Most of the time, they couldn't even hear the prayers of their own followers unless they were exceptionally devout.
But there was one thing they could sense one hundred percent of the time, and that was large-scale sacrifices or when actions related to their divine offices were performed, requiring at least five hundred people even for those with strong divine power.
For example, the god of war Tempus could sense all conflicts in Felen that involved more than five hundred people. For fights involving fewer than five hundred, he wouldn't be aware unless he had an incarnation present or a devout follower praying.