I will never forget my worst ever job interview. I was 22, fresh out of university and probably a little over-confident in what I was applying for. Actually the conversation itself wasn't so bad – I gave an adequate presentation (although at the time I'm sure I thought it was worthy of TED) – and I talked up my limited skills and experience to the very limits of plausibility. No, the really awful part was the phone call afterwards where the lead interviewer told me I'd been unsuccessful.

She could probably have given me a bit of generic feedback and wished me the best of luck. Instead, she saw an opportunity to explain in painfully colourful detail exactly why they would never have hired me in a million years; why my inability to display relevant skills and qualifications were only drowned out in their unsuitability by my crushing lack of character. She actually told me that I was the worst candidate they'd seen that day, and added with some frustration that I should never have applied. I was crushed, and yes, this was a Christian organisation.

It turns out that sometimes even those of us who claim to follow Jesus aren't brilliant at giving helpful feedback. Of course, that isn't just manifested in examples like this, where the speaker metaphorically uses a sledgehammer to crack a nut. In many cases, we find ourselves unable to give a bit of honest constructive criticism for fear of causing offence or upset.

In Ephesians 4, Paul writes that one of the key marks of Christian maturity is that we 'speak the truth in love' (Ephesians 4 v 15). This is the answer in a nutshell – we should find ways of building one another up through kindly-presented criticism – but of course that's much easier in theory than practice. So how exactly do you communicate kindness and critical feedback at the same time?

The first step (after praying that the conversation will go well) is to ensure we have clarity about what we're trying to communicate. If we want to talk about a specific issue or problem, then a vague understanding of it on our part can lead to a conversational conflict. Specific examples are helpful (as long as they're not presented as a case file of evidence!), and ensure that the discussion doesn't feel like a communication of general bad feeling.

After this, we should carefully think about thelistener, how they will receive the feedback, and how best to communicate it. For some people, a face-to-face conversation is actually the worst context to receive a difficult piece of criticism, so we might want to use alternative means of communication such as a letter or phone call. Perhaps even more importantly, we should try to consider their feelings, as well as any mitigating circumstances which might have caused the issue, in order that we can demonstrate understanding.

We should also always aim to demonstrate compassion for the person to whom we're giving difficult feedback, and assume the best of their motives and intentions. It is fine to question a specific behaviour, but we are on much trickier ground when we question the motivations behind it. Instead of doing that, our aim should be to care about them, how they receive this feedback, and how things might improve for them as a result.

A final step then, is to consider in advance what a positive outcome would be for the person and the context in which you're giving the feedback. This should also be communicated as part of the conversation; little is achieved by telling someone they're a terrible public speaker, whereas suggesting ways that they could improve (or potentially pursue an alternative gifting!) is a much more helpful approach, which leaves the listener with somewhere to go, rather than a general sense of personal devastation.

We struggle to 'speak the truth in love' for a whole range of reasons from busyness to blundering, but most of the time we fail to deliver helpful feedback to each other because we just don't think about it in advance. These few steps aren't much more than common sense, but they might just help you to practice this mark of maturity a little better, and perhaps they might even have saved me from all those tears right at the start of my career.

Martin Saunders is a contributing editor for Christian Today and the deputy CEO of Youthscape. Follow him on Twitter @martinsaunders.