On the surface there is nothing wrong with wanting things. We've all been there. I've been there. I want things. New things. Pretty things. Shiny things.
Here's the problem: Happiness from stuff is temporary.
You're happy for a short time with your shiny new thing. And then you start craving and aching for that next, newer, better thing. It's a never ending chase. A constant cycle of ups and downs. Always seeking what you believe will bring happiness, only to soon feel empty and need something else to fill the void.
For some people it's not only things. It's a belief that if circumstances were different, they could finally be happy. A better job. Moving to a different home/city/state. Having a boy/girlfriend, finding a spouse, or getting a divorce. Having a child. Losing weight.
And what happens if we don't get that item or circumstances we believe will bring us joy? We find ourselves feeling angry, resentful, frustrated, and lost.
I am not saying this because I am in need, for I have learned to be content whatever the circumstances. I know what it is to be in need, and I know what it is to have plenty. I have learned the secret of being content in any and every situation, whether well fed or hungry, whether living in plenty or in want." ~ Philippians 4:11-12 (NIV)
Paul had "learned the secret". True happiness isn't found in stuff. Or based on the circumstances we are in.
“Do not store up for yourselves treasures on earth, where moths and vermin destroy, and where thieves break in and steal. But store up for yourselves treasures in heaven, where moths and vermin do not destroy, and where thieves do not break in and steal. For where your treasure is, there your heart will be also." ~ Matthew 6:19-21 (NIV)
Real, lasting happiness comes in knowing the grace and glory of God and accepting all the treasures and gifts He has in store for those willing to accept it.
"So we fix our eyes not on what is seen, but on what is unseen. For what is seen is temporary, but what is unseen is eternal." ~ 2 Corinthians 4:18
Not to say that as Christ followers we don't know sadness, difficulties, or times of trouble. But during those times there is a faithful, eternal, loving God watching over us, comforting us, and ready to bring us back to a place of joy and happiness.
"And we know that in all things God works for the good of those who love him, who have been called according to his purpose." ~ Romans 8:28 (NIV)
"For I know the plans I have for you,” declares the Lord, “plans to prosper you and not to harm you, plans to give you hope and a future." ~ Jeremiah 29:11(NIV)
God wants good things for us. He wants us to know joy. He wants our happiness. We just have to place our trust in him. And look to Him for our joy. Once we manage to start doing that, we will find an even deeper happiness in the things, people and circumstances in our life.