Unbelief creates a lack of understanding

And now because of their unbelief they could not understand the word of God; and their hearts were hardened. Mosiah 26:3

This verse intrigues me. What do I not understand because of my unbelief? An express causal relationship is portrayed here.

Now this doesn't imply that every lack of understanding is caused by unbelief, but that unbelief is indeed a cause of a lack of understanding.

Unbelief creates lack.

The thirteenth article of faith teaches "we believe all things." I've never thought that to imply gullibility. At the same time, the word used is all.

I've oft pondered what could be meant by this. I have a number of thoughts, none of which I am completely confident on, but I want this post to be short and sweet, so perhaps another day.