John, if I might add a word here. If believing is enough then why isn't Satan saved?
Demons believe God is One, they do not, nor could they, nor would they believe in, (trust in, depend upon and cling to) Jesus Christ as their Lord and Savior.
Here we go again!
The answer is because demons trust Satan, they do not trust God. The answer is they do not believe God is whom He said He is
A lot of people who are not Christians, who are non believers believe Jesus existed, most of them believe He was a very wise man, they believe He was a very good man, some even believe He was highly gifted and developed in spiritual matters with supernatural power and ability to do miraculous works yet.....
THEY DO NOT BELIEVE HE IS WHOM HE SAID HE IS
Like the Pharisees who heard Jesus and saw His miracles, saw Lazarus raised from
the dead and knew very well Jesus did it yet...........
They did not believe Jesus was Whom He said He was!
Even Lucifer was cast out of heaven because he believed he was above God, better than God....
So obviously he did not believe God is The Almighty God, The One True and Living God...
At least it should be obvious
In the end comparing what demons believe to what we who are God's people believe is the height of foolishness, for there is no comparison and shows a total misunderstanding of the intent of what James was saying in James 2:19
Clearly Satan and demons have made their choices based on what they believe
And we have made ours
Believing is the foundational fundamental basis of Our Faith and the most novice of believers can cite 10-20 scriptures to that 1 verse, that say as much.
Satan would want nothing better than to make Christians believe, that believing is not enough, for if you believe that, your Christian walk is weakened and at best made ineffective and impotent
Romans 10:10 for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation. Yes demons know who Jesus is, but Satan is their lord so Satan or his demons do not and will not confess Jesus as Lord
that if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; Romans 10:9