I’m not surprised by this study since religion gives you a way to cope with the anxities of life and in some cases a reason for them.

Religious people are better able to cope with shocks such as losing a job or divorce, claims the study presented to a Royal Economic Society conference.
Data from thousands of Europeans revealed higher levels of “life satisfaction” in believers.
[…]
Professor Clark, from the Paris School of Economics, and co-author Dr Orsolya Lelkes from the European Centre for Social Welfare Policy and Research, used information from household surveys to analyse the attitudes of Christians – both Catholic and Protestant – not only to their own happiness, but also to issues such as unemployment.
Their findings, they said, suggested that religion could offer a “buffer” which protected from life’s disappointments.
Professor Clark said: “We originally started the research to work out why some European countries had more generous unemployment benefits than others, but our analysis suggested that religious people suffered less psychological harm from unemployment than the non-religious.
[…]
He said that the benefit might stem from the increased “purpose of life” felt by believers.

This isn’t surprising to me at all. If I know that problems in my life are used by the Lord to produce fruit, then suffering takes on new meaning and it’s something I can endure with confidence in the Lord that he will see me through it and it will be used for my betterment. How can I be so sure that my suffering has a purpose? The New Testament is filled with words of encouragement to help us endure and persevere in the face of suffering:

Romans 5:1 Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. 2 Through him we have also obtained access by faith into this grace in which we stand, and we rejoice in hope of the glory of God. 3 More than that, we rejoice in our sufferings, knowing that suffering produces endurance, 4 and endurance produces character, and character produces hope, 5 and hope does not put us to shame, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us.
Romans 8:6 The Spirit himself bears witness with our spirit that we are children of God, 17 and if children, then heirs–heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him.
Philippians 1:29 For it has been granted to you that for the sake of Christ you should not only believe in him but also suffer for his sake
James 5:13 Is anyone among you suffering? Let him pray. Is anyone cheerful? Let him sing praise.

Suffering draws me closer to Christ and conforms me to his image:

Philippians 3:10 that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death, 11 that by any means possible I may attain the resurrection from the dead.
2 Timothy 2:3 Share in suffering as a good soldier of Christ Jesus.
1 Peter 2:21 For to this you have been called, because Christ also suffered for you, leaving you an example, so that you might follow in his steps.
1 Peter 4:12 Beloved, do not be surprised at the fiery trial when it comes upon you to test you, as though something strange were happening to you. 13 But rejoice insofar as you share Christ’s sufferings, that you may also rejoice and be glad when his glory is revealed. 14 If you are insulted for the name of Christ, you are blessed, because the Spirit of glory and of God rests upon you.

Also, knowing that the suffering of this life doesn’t compare to the glory that is to come, gives us the ability to endure whatever comes our way:

Romans 8:18 For I consider that the sufferings of this present time are not worth comparing with the glory that is to be revealed to us.

If you have this understanding, is it any wonder that Christians could be content with whatever situation we are in?

Philippians 4:11 Not that I am speaking of being in need, for I have learned in whatever situation I am to be content.

Of course, it’s not always easy to feel that way and it’s a process we struggle with. We don’t enter the suffering ready to handle it as the Roman 5 passage makes clear.
And then there’s this:

Terry Sanderson, president of the National Secular Society, which represents the interests of atheists and agnostics, said that studies purporting to show a link between happiness and religion were “all meaningless”.
“Non-believers can’t just turn on a faith in order to be happy. If you find religious claims incredible, then you won’t believe them, whatever the supposed rewards in terms of personal fulfilment.

Unfortunately she has this backward, no one is saying believe so you can be happy, it’s a cause and effect. Happiness flows from religion. I didn’t became a Christian to be happy, I became a Christian because I believed what the Bible said about Jesus. Happiness has flowed from that. How can you not be happy when the God of the universe has poured out his love on you?

Romans 5:5 and hope does not put us to shame, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us.

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