5 Now this is what the LORD Almighty says: "Give careful thought to your ways. 6 You have planted much, but have harvested little. You eat, but never have enough. You drink, but never have your fill. You put on clothes, but are not warm. You earn wages, only to put them in a purse with holes in it." (Haggai 1)
In every aspect of their lives, they were dissatisfied. No matter what they did, they didn't have enough and didn't accomplish as much as they had hoped for. They were living their lives with less than the bare minimums.
Why were their efforts amounting to nothing? Was it because they weren't trying hard enough? Did they not have the right attitude? Did they have the wrong motives? What was causing their failure?
Basically, they did not turn to God for anything. Without God, everything we do will be less than it can be and, likewise, more painful and dissatisfying than it has to be. I like how God reminded them and how He reminds us: "Give careful thought to your ways." Really consider what you're doing. Are your efforts amounting to anything?