"Now this is what the Lord Almighty says: 'Give careful thought to your ways. 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.'" NIV translation
This wakeup call is for God's people to simply look around them at their efforts and examine the results. They had trusted in their own efforts instead of the provision of God and didn't even have all that they needed. This call is for us as well in that many today are struggling under their own efforts and their own priorities. We might ask ourselves: "How's that working for you?" That is basically what God is saying to His people here.
"This is what the Lord Almighty says: 'Give careful thought to your ways. Go up into the mountains and bring down timber and build the house, so that I may take pleasure in it and be honored,' says the Lord." NIV translation
Now, we see the call to put God first. He tells them to focus on building His house and this same call is for us today. The exiles needed to gather wood to build the house while we need to gather people that accept Jesus Christ as their Lord and Savior. There are many groups of believers today that are still gathering building materials to build a big fancy house of the Lord instead of realizing that the house is built in the hearts of His people.
"'You expected much, but see, it turned out to be little. What you brought home, I blew away. Why?' declares the Lord Almighty. 'Because of my house, which remains a ruin, while each of you is busy with his own house. Therefore, because of you the heavens have withheld their dew and the earth its crops. I called for a drought on the fields and the mountains, on the grain, the new wine, the oil and whatever the ground produces, on men and cattle, and on the labor of your hands.'" NIV translation
Because their own homes had been their priority, God removed His hand of provision from the people. They had trusted in their own efforts and forgot that everything they had came from God.