That's not true.
Luke 4:41But they certainly can't be trusted.Moreover, demons came out of many people, shouting, "You are the Son of God!" But he rebuked them and would not allow them to speak, because they knew he was the Christ.
'demons came out of many people, shouting, "You are the Son of God!"'
Interesting too how Jesus said that not all who cry "Lord, Lord" will be Saved. I suppose these demons are some who fit the bill.