It is written like this:
Knowing this, who dares deny?
Knowing this, who dares fail to worship?
Knowing this, who dares worship the false gods of the Koran and bible?
It is written more as a wake up call to readers, rather than a threat. He says this after establishing himself to the reader as the only God, with dominion over All.
So he asks, "knowing this, who dares fail to worship?" He asks, do you still deny me after this knowledge, do you still not partake in my knowledge and mysteries after knowing this?
It is a call to the consciousness of the reader to snap out of their dull and godless state, and open up to him once again, it is also a call to the reader for the benefit of them, as he explains right after:
Know that who knows me will I cast into paradisiacal gardens of my pleasure!
Knowing Satan involves living as a being partaking in the ascending path presented by His teaching, i.e, to worship Him. As without doing so, you cannot know him. He just explains this here, also meaning that those who follow the false faiths do not know Him and will be without His Blessings, i.e, be cast into affliction, which is the natural result of being without His Blessing. Asking the reader,
"Do you dare rescind my blessings to follow the godless false faiths of the koran and bible?
".