To “always tremble before God” is to “always be extremely fearful” or “always be supremely reverential.” Clearly the focus isn’t walking around afraid of people, places or things – but having a healthy respect for my place in God’s universe.
It should be noted that the words “before God” are not in the ancient text. But they are a reasonable understanding of this verse’s message, as suggested by the translators here.
Either way, this person is one with a true understanding of Someone bigger than him or herself. Consequently, they’re “blessed” or “happy” as they live out being such a person.
On the other hand, “whoever hardens their heart” is someone “cruel” or “severe” in their heart. They can be that way toward God or others.
The consequences of being this person is that he or she “falls into trouble,” or the normal translation for that word – “falls into evil.”
Every day we have the opportunity to choose whether we want to look at life from the perspective that God is out there and has a wonderful plan for my life. Or the alternative – there’s nothing more out there and, then, there’s really no reason to care.
It’s our choice and we have to right to choose what we want. But we’ll also have to live with the consequences!