Do you really believe that what you believe is really true?

I heard a teacher describe it as a "haunting question." Let me write this again:

Do you really believe that what you believe is really true?

It's haunting because it cuts to the heart of our belief system.

If I really believed, why do I not always do what the bedrock of my belief system (the Bible and the Holy Spirit) says?

In recent weeks, on two occasions, I have been pierced with clean through by my own unbelief. The first time I failed to act on my beliefs, and again when I heard this haunting question and recognized the depth of my unbelief.

Lord, I believe. Help me in my unbelief. Give me more faith, I humbly ask.