"'Therefore I will block her path with thornbushes; I will wall her in so that she cannot find her way.'" NIV translation
As Israel turns to look for another provider, God says that He will block these efforts. God can place tough times in front of us for our own good. We can then stop, examine ourselves, and turn back to Him or we can continue to struggle.
"She will chase after her lovers but not catch them; she will look for them but not find them. Then she will say, 'I will go back to my husband as at first, for then I was better off than now.'" NIV translation
This verse describes how the physical beauty of the prostitute will fail and she will be unable to attract a man to provide for her.
It reminds us that we can look to the temporary things of this world or we can set our sights on things above that will last.
"She has not acknowledged that I was the one who gave her the grain, the new wine and oil, who lavished on her the silver and gold - which they used for Baal." NIV translation
Gomer did not remember who had provided for her needs just as Israel had forgotten that it was God. God had not only provided for their needs but had also made them rich (silver and gold). Instead of acknowledging that it was from God, they turned and used the riches to worship Baal. Baal means "master" in Hebrew and Baal worship was simply making something else master over you.
We may say that we don't have Baal worship among us today but there are those that have become slaves to their fancy homes, cars, or other possessions and it is the same principle.
"'Therefore I will take away my grain when it ripens, and my new wine when it is ready. I will take back my wool and my linen, intended to cover her nakedness.'" NIV translation
God tells His people that, since they do not want to acknowledge Him as the provider, He will remove His blessing from them.
"So now I will expose her lewdness before the eyes of her lovers; no one will take her out of my hands." NIV translation
God is light and light exposes the evil things that are done. God is proclaiming that the woman (Israel) will be publicly judged for their adultery. Many try to hide their sins from God in hopes that He will not see them but when the Light is applied all will be exposed. At that point, our only hope is in Jesus Christ and his payment for our sins through the blood that He shed.