Intellectually believing something is true.
Taking a wild risk and assuming God will rescue me.
Being so optimistic that I have no doubts.
Trusting God enough to do what he says.
1 Samuel 15:1-24
Doubt that writes God off.
Doubt that disobeys.
Doubt that worries, but still obeys.
We can't become righteous by good living and religious rituals.
We can be declared righteous by faith alone in Christ alone.