I recently heard a brilliant talk about why (and how) Christians shouldn't worry. I thoroughly recommend the talk, and others by David Legge.
David included this illustration:
There was a man and he was terribly troubled with anxiety, and everybody knew him for it. One day he was walking along the town whistling and singing, and the people looked at him and said: 'That can't be the same man!'. They stopped him and said: 'What's wrong with you, that you're not worrying?'. He said: 'Well, I'm paying a man to worry for me' – that's right! 'You're doing what?'. 'Paying a man'. 'How much are you paying him?'. '£2000 a day'. 'Where are you getting that?'. He says: 'That's not my problem!'.
Friends, we're laughing at that, but there is a great truth there, isn't there? If God is in control, and God cares about you, why are you staying up all night late into the wee small hours, when He who neither slumbers nor sleeps is covering you? Now listen, we either believe it or we don't – and this is our problem: we don't!
The great thing is, we really can act like someone who has someone to worry for them – only it won't cost us £2,000 a day. I know this is true. Putting into practice consistently – ah, there's the challenge.
So next time you see me in the street, feel free to ask me why I'm not whistling 🙂