How can you tell whether something is sinful? Easy-peasy: just ask yourself, 'Would I enjoy doing this?' If the answer is yes, it's a no-go.

That, at least, is how Christians are perceived by the outside world. According to this view – easily caricatured, but not without a hint of truth – God hates anything fun: the more begrudging the obedience, the better. No wonder, then that the video of Rev Ben Brady dancing caused such a stir: it showed that the heart of worship was not rule-based obedience but elation and excitement. There's something contagious about joy.

When my church goes to a club for its karaoke and dancing social event, we don't label it 'evangelistic' or 'outreach', yet it never fails to spark conversations. Not only are the staff bewildered by the fact that a church has taken over their dancefloor, but the way in which we dance is also remarked upon. Not because we cluster in single-sex groups or avoid wiggling our hips (the ways in which some might argue Christians should be distinctive). Rather, because they see that our dancing grows out of a place of joy and a sense of freedom. Have you ever seen people 'dance' by shifting their weight drearily from one foot to the other? The fear that others will think we look ridiculous, uncool or unattractive rigidifies our frames and kills our joy. But when you know that God delights in you relishing his creation and how he made you, and your body manifests the freedom which flows from that knowledge, then you're not dancing in the way 'the world' dances.

The contagiousness of joy, though, makes it a threat to those interested in control – religious or otherwise. In Iran, for example, a country with strict laws on dancing, four girls were recently arrested for posting videos on Instagram of themselves dancing (in recent years, there have also been multiple arrests for teaching Zumba and dancing to Pharrell's Happy). Of course, issues of modesty also stand behind these laws. But I believe that a fear of pleasure – especially in such an embodied form, and even more so when the bodies in question are female – is also at play.

When we imagine God is like the Iranian authorities, watching for us to step out of line and quick to retribution – we become paralysed. In 2 Samuel 6, David, angry with God for punishing Uzzah for mishandling the ark of the covenant and afraid of a similar fate, does not bring the ark into Jerusalem and leaves it with Obed-Edom. But when he sees God bless Obed-Edom's house, he realises that the ark of God – the presence of God – is meant to be a gift, not a curse. Then, not only does he bring it into Jerusalem, but does so while dancing with abandon.

Our walk with God should be light-footed: his presence in our lives should open us up to a richer, fuller sense of joy 'for God gave us a spirit not of fear but of power and love and self-control' (2 Timothy 1:7). Fear of our own sinfulness should not paralyse us but help us realise the extent of God's grace as we try our best to please him (and undoubtedly make mistakes along the way).

In response to the recent arrests, more Iranian women have filmed themselves dancing as a form of solidarity, protest and resistance. One of their hashtags translates as 'dancing is not a crime'. To seek again delight in music and the way in which our bodies instinctively respond is a beautiful act of defiance that perhaps shows the brutality of the regime better than any angry tirade could. It is to choose to not merely be afraid and embittered but, in the face of a crackdown by authorities, to keep joy alive. In Hope in the Dark, the activist and writer Rebecca Solnit writes: 'Joy doesn't betray but sustains activism. And when you face a politics that aspires to make you fearful, alienated, and isolated, joy is a fine initial act of insurrection.'

Keeping the fires of faith and joy burning is, I believe, part of our calling as Christians. For we could only be joyful in a world full of brokenness and evil if we had the audacity to believe that love could really triumph. And that is the faith that we boldly declare and, yes, embody – in our dancing, in our play, in our laughter, and in all our actions that would be futile and shameless if the fate of our world was undecided.

So feel free to tear up the dancefloor out of gratitude for the presence, faithfulness and love of God and out of trust that his kingdom really will come. Of course, as David found, the Michals of the world will look upon such exuberance with disapproval. But taking our cue from Taylor Swift's 'Shake It Off', in the presence of haters, we, like the women of Iran, can choose to dance.

Florence Gildea is a writer and researcher.