This is a great verse that speaks to the major power and importance of the word of God.
The word of God is living and active. Sharper than any double edged sword, it penetrates even to dividing soul and spirit, joint and marrow; it judges the thoughts and the attitudes of the heart.
When thinking about just how powerful something has to be to divide soul and spirit, I ended up looking both of those words up to see their definitions. From a definition standpoint, they can hardly be separated. From a materiality standpoint, they also can hardly be separated since they are both immaterial. That to me says POWER!
The bible is so often taken out of context and/or "judged" sometimes but what this verse is saying is that the word of God judges our heart. It is extremely relevant (and powerful) in our current, real-life circumstances and our hearts should be aligned with what it says instead of what we want or don't want it to say. It reminds me of something I heard a couple of years ago and it has stuck with me. Instead of looking at the bible through a "worldly" filter, look at the world through a "biblical" filter.