They are under satanic control,
They are rebellious against One True GOD,
They are blinded,
etc
If you give sincere warning that something bad will happen tommorow, they may go about attacking you instead of preventing it until it happens. Better to build a different "World" and leave them alone.
Warnings will keep coming for those willing to listen.
Always be on the good side. Never mix good with evil!
Like what Noah did right?before the Big Flood happens?
Anyway that is People attitude,most of us are bright at their own beliefs so instead of listening to warning,they will provoke you to prove more than what you have mentioned.