Pope Francis has been preaching it to the whingers at the Vatican. He has posted a sign on his door telling complainers to stop whining.

'It is forbidden to complain,' he says on the sign in Italian at his St Marta apartment, Vatican Insider at La Stampa reports.

Here are 3 Bible passages that show why the Pope is right, and why Christians should not waste their time whining and playing the victim.

Numbers 14: 'So all the congregation lifted up their voices and cried, and the people wept that night. And all the children of Israel complained against Moses and Aaron, and the whole congregation said to them, 'If only we had died in the land of Egypt! Or if only we had died in this wilderness!'

We all know people for whom the bottle is half empty, not half full, no matter how much you try to help them. Here, in this passage, we see how God had finally led his people to the promised land and yet all they did was whinge about it and some even suggested returning to slavery in Egypt. In the modern world, many of us have known what it is to be slaves to our defects of character – to addictions, or to things that are bad to us. Sometimes it can seem more comfortable to live in these bad habits than try and leave them behind. Giving them up to move into a 'promised land' of freedom from the bondage of self can seem almost impossible. It can also be frightening. People who try and help us on these journeys will not respond to whingeing and whining. A positive outlook is needed. My mother used to say, 'There's no such word as can't.' There is of course. What she was really saying was the same as the Pope: 'Stop complaining.'

Matthew 20: So when evening had come, the owner of the vineyard said to his steward, 'Call the laborers and give them their wages, beginning with the last to the first.' And when those came who were hired about the eleventh hour, they each received a denarius. But when the first came, they supposed that they would receive more; and they likewise received each a denarius. And when they had received it, they complained against the landowner, saying, 'These last men have worked only one hour, and you made them equal to us who have borne the burden and the heat of the day.'

The parable illustrates how even genuine acts of mercy can be wilfully misinterpreted by anyone determined to see whatever happens in the world as a personal insult to the self. In paying an equal wage to all, no matter how long they worked that day, the vineyard owner was not denigrating the work of those who spent hours slaving in the hot sun. He was being merciful to the ones who arrived late and worked just one hour, understanding that they and their families needed the money as much as the early starters. Pope Francis must identify with this. His exhortations to mercy over the past four years have been turned against him by some who seemingly would prefer a harsher, more judgmental and unforgiving leadership. Pope Francis preaches the Bible's gospel of grace – and he has shown he can do it with humour, always an effective way to get a difficult message across.

1 Corinthians 10:10: Do not grumble. Philippians 2:14-16: Do all things without grumbling or questioning, that you may be blameless and innocent, children of God. James 5:9: Do not grumble against one another, brothers, so that you may not be judged; behold, the Judge is standing at the door.

Many Bible passages explicitly enjoin against grumbling. Yet it is a habit of too many of us. How easy it is to complain about our vicar, or the music in our church, and imagine how much godlier things might be at that more evangelical, or more Catholic, church in the next village or town. It is true people love to complain and Christians are no exception. The pastors we complain about in our parishes will certainly complain just as much about us in their own vicar meet-ups: 'Oh why won't so-and-so help out more in church? All she does is sit there and moan.' Or, 'Why does so-and-so insist on stacking the hymn books that way when he knows I prefer them this way?' But it is too easy – and too bad – a habit to get into. And whether we like it or not – and everyone from time to time does love a good moan – the Bible is clear about one thing: God doesn't like it one bit.