Doesn't Jesus say that the demons also believe, and trermble?
Lets look at that verse and stop using that like its the same as those who trust on and have faith of Christ.
James 2:19 Thou believest that there is one God; thou doest well: the devils also believe, and tremble.
Thats rather different than this.
Acts 16:31 And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.