In Samuel 1:19-20, the people wanted a king like the other nations. In that desire, they were rejecting God as their king. When Samuel asked God what he should do, God said warn them, but if they still want a king, let them have a king.
The end result was less than what God intended them to have. They substituted a king for God, and God let them do it.
As Christians, we tend to be envious of the world and want what the world has. When we want and seek after what others have, even if what we want is not bad in itself, we reject God. If we do not relent he will give us what we want, but we will not be better off for it.
People everywhere are tempted to want what others have and want to be like people around us, believers included. This is not a matter of following a godly example, but of the desire to be like others, to fit in and to have what they have. God does not favor that desire. He made us for something else. He calls us to Himself, and He wants us to be set apart.
We are warned about the consequences of seeking our own desires, but God will, ultimately, let us have our own way. God will not hold back the dam that holds our desires. He will let us go:
“Therefore God gave them over in the sinful desires of their hearts…. They exchanged the truth about God for a lie, and worshiped and served created things rather than the Creator….” (Romans 1:24-25)
The ultimate fate of the people or person who continually wants something other than God is like the dam that is breached and no longer holds the water back. God gives us over to those desires. We get what we want, but not the good that God wants to give us.