Names are important. Labels matter. To see evidence of this, look no further than the contemporary Church, where titles like 'evangelical', 'liberal', 'biblical' or 'progressive' are frequently fought over.

An article on this site published yesterday featured controversial UK Baptist minister Steve Chalke, but the labelling of Chalke as an 'evangelical' frustrated many on Twitter, who felt Chalke's liberalised position on sexuality meant he no longer deserved the designation.

Others replied that if Chalke self-identified as an 'evangelical' then he was one.

So which is it? 'Evangelical' doesn't designate a specific denomination in the way that the formal identities like Protestant and Catholic do. There's something of an open season on the name – some are keen to claim it for themselves and others deliberately reject it – but is anyone clear what it actually means?

Etymology doesn't always equal meaning, but it can tell us where words came from. The word 'evangelical' takes its root from the Greek New Testament word euangelion that we translate as 'gospel' or 'good news'. It's used to describe the message of Jesus and the Kingdom of God. Those who orientate themselves around this word then, are those who want to be primarily defined in relation to Jesus' good news.

Taking this label may be an attempt to distance oneself from 'tradition' or 'religion' and focus on the 'core' of what Jesus was about. It may also be used to emphasise an immediacy and a passion to 'share' this good news, in the same way that Jesus preached the euangelion to first century crowds, and the way that the New Testament 'Gospel' writers are known as 'evangelists'.

Being defined essentially by news, an 'evangelical' can be someone who posits that through God something has changed – an event has taken place – and human beings should participate/respond in light of it. But all this merely captures a spirit, a direction – not a precise doctrinal creed.

To speak historically of evangelicalism, is to speak about a particularly Protestant phenomenon that's matured mostly in the past century. Historian David Bebbington offers four qualities that define 'evangelicalism': Biblicism (a focus on the Bible as the foundation for truth), Crucicentrism (a focus on Christ's substitutionary, atoning work on the cross), Conversionism (the belief that repentance conversion to Christian faith is absolutely necessary for salvation) and Activism (the belief that the Gospel needs to be spread through concerted human effort).

These are helpful theological categories – still accurate for many today – but 'evangelicalism' also has a distinct political legacy. In the US, the movement has become largely aligned with particularly conservative, Republican politics. A caricature of 'right-wing evangelicals' as passionately pro-life (or anti-abortion), pro-gun, pro-war, and opposed to LGBT rights, taxes and free healthcare has not always been far off the mark. The label has also become associated with a fundamentalist, literalistic interpretation of Scripture – which brings with it a suspicion of human science and evolutionary theories about the origins of humanity.

These are highly political, polarising positions, which has led to many distancing themselves from the title of 'evangelical'. This came to the fore in the 2016 US election, when 80 per cent of 'white evangelicals' cast their vote for Donald Trump: many Christians who were passionate about the 'gospel' but adamantly opposed to Trump resented the association.

A negative reaction to the word has carried over to the UK as well, where in secular politics being labelled as an 'evangelical Christian' is an efficient way of ensuring your unpopularity. It sounds odd at best and dangerously illiberal at worst.

But despite its political baggage, some have attempted to reclaim the word. Former megachurch pastor Rob Bell, even since facing a 'farewell' from popular conservative evangelicals like John Piper for his shifting views on eternal damnation and later, same-sex marriage, has still said he identifies as an 'evangelical' – summing it up as being about 'good news for everybody', and not merely a name for a 'narrow voting bloc'.

Other popular figures aren't reclaiming the name but rejecting it: Christian hip-hop artist Lecrae has openly talked about 'divorcing' white evangelicalism after he faced a backlash for speaking up about about racial injustice in America.

Many are keen to resist a philosophy of 'self-identification' that essentially says 'you're an evangelical if you say you are'. They want the word to be stricter, to possess more meaning. The problem is evidently that 'Christians' are a complex, diverse group, and positions on issues like gay marriage appear to be shifting frequently among certain leaders. That means some, like Chalke, may want to affirm the title they once comfortably held as 'evangelical', while others are keen to strip them of it. Chalke still sees his beliefs as 'biblical', his opponents disagree. Who draws the line?

In my interview with Chalke one of his main points was that so many jump from disagreement to complete dismissal, as debates about who's 'in' or 'out' of evangelicalism show. It's not that all conservatives are ungenerous 'gatekeepers' determined to exile those they don't like – it may just be that they want their labels to mean something very specific. And of course names – and the values and ideas they point to – are important if communication is to mean anything.

None of this offers any specific answers to the puzzle of what it means to be 'evangelical'. More direct descriptors like 'Reformed', 'conservative-evangelical' or 'progressive' can be helpful.

But the instinct to label can also be deeply unhelpful, as I've suggested with recent church clashes over homosexuality. Labels can be an attempt to reduce or ignore, rather than understand. Grace and humility in interactions should be a mark of Christian witness – can this include a degree of charity about the 'names' that we take and give to others?

You might say that's particularly appropriate when the word 'evangelical' is itself a word of hope and generosity. Euangelion announces 'good news' to those who listen, and invites participation in that changed reality.

Perhaps there is more to add, since Christian faith can be complex. But before it descends into name-calling and cruel division, that 'good news' is worth remembering.

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