I don't think the passage, Hosea 3:1-5, is pertaining to a woman specifically. In the old times, the Israelites were known for making idols and worshiping other gods. What better way to define it than by the use of the word, harlot.
Harlotry and idolatry mean the same thing in the Old Testament context. All throughout the Old Testament, the people of God disgraced His name by building golden idols for them to worship. They were not content with the provisions, blessings and mercy they received from God. They wanted a god that they can see, touch or even smell.
Moreover, these people did nothing but evil in the sight of the Lord. They were filthy and unworthy. They committed adultery among each other, brothers and sisters included.
Despite this unbearable fact, the Lord continued to hear their pleas whenever they cried to the Lord to forgive them. God's love for them was so great that He mercifully forgave them and showered them with blessings.
This is the Lord's message to Hosea.
"Go again. Love the people who have done evil things to you. Love those who curse you. Love those who have hurt you. Love them as I loved the children of Israel when they played the harlot with other gods and disgraced My name."
In the passage, Hosea bought the woman for a price. But actually, it is God who bought us for a price. Fifteen shekels may be a lot for the Israelites in their time, but the Lord paid a much higher price - His one and only Son, Jesus Christ. He was willing to sacrifice His only Son to save a world of sinners!
And the Lord instructs us,
"You shall not have any other gods before Me all the days of your life. Your devotion and love is only for Me. Do not equal Me to the things of this world nor to the people I placed before you. Do this, and so will I to you."
The message is clear, but I understood the real meaning only now. Let's focus our eyes, our lives, our hearts on the Lord, our Rock and Fortress. I may fail you, and you may fail me. But the Lord can't and will never do that.