Every Sunday when it's time for the sermon my husband and I reach for our phones and turn to our Bible apps.

I have to admit I've occasionally thought of checking my Twitter timeline, but so far that particular temptation has been resisted. My friend, however, who is finding it very hard to engage with church at the moment, has no such qualms.

'I check my emails and read my book on my phone,' she told me recently, and I felt a bit put out. But I figure at least she's in church, physically present if not mentally.

The issue of whether mobile phones should be used in church is often discussed and last week I read a great post on the Big Bible Project website by Bryony Taylor (@vahva if you're on twitter).

She made the point that when we use our phones in church we may be upsetting or distracting worshippers who may misinterpret what we're doing and think it's disrespectful. Commenters on the blog asked if there's a difference between using a mobile phone and a notebook. After all, you can doodle or write your to-do list on a piece of paper as much as you can play Angry Birds on your phone.

I'd like to go one step further and ask this: If I'm in church with my phone on silent and being generally discreet, what business is it of anyone else what I'm up to?

And if the 'distraction' of a mobile phone is merely making the man behind me wonder whether I'm really paying attention, exactly whose problem is that? Christians do seem very concerned about what other people are doing… Is 'so and so' really saved? Can you be a Christian if you're in a sexual relationship but not married? The debates go on...

Perhaps I should have told my friend that her behaviour was wrong. I didn't, because I want her to come to church again; I want her to feel welcome and not judged. And besides, if she wants to read the latest Alexander McCall Smith rather than listen to the sermon, isn't that between her and God?