Faith -v- Unbelief

Q: What is the opposite of faith? It’s unbelief.

In his song Precious Angel, Bob Dylan observes:

Ya either got faith or ya got unbelief and there ain’t no neutral ground.
The enemy is subtle, how be it we are so deceived
When the truth’s in our hearts and we still don’t believe?
Shine your light, shine your light on me

As Christians, we know he is on to something.