It was a night I will never forget. Forty young people were packed into the tiny youth hall of our church and 150 adults were eating, listening to poetry and telling jokes in the main hall.

It was cramped enough when everyone was seated, but when the music started it became a party like no other. Kosovar dancing filled the room with hilarity and laughter and condensation. My glasses got so fogged up I stepped outside to grab some air. It was then that a Muslim man in his twenties joined me, put an arm round my shoulder and shouted: "I never could have imagined this. My last contact with Christians was when the Serbs tried to execute my family. Now we are dancing in a church."

I could never have imagined it either. Seven years earlier, I had volunteered as a cross-cultural missionary and requested a placement in Russia. A three-year stint in Albania had made my heart sink at first. Another language to learn – and one which would be virtually useless after the three years. How wrong I was. The Kosovan crisis displaced tens of thousands of Albanian speakers and many of them ended up in Harrow, where I was leading a church. We ran English classes for the women and Albanian classes for the children. We acted as referees for passport and asylum applications. We put on cultural evenings with folk music and local delicacies. We did everything we could to make the Kosovans feel welcome.

But was it also right for us to offer the opportunity to discover more about the Christian faith?

I wanted to put the record straight and that the ethnic cleansing conducted by the Serbian army was not an accurate outworking of the teaching of Jesus to love your enemies. I wanted to explain the "Jesus is Lord" text in large silver lettering on the wall – that Jesus really is the rightful ruler of all the nations and every heart. I wanted to worship God with my new neighbours as well as dancing with them to their folk songs.

Some would say that serving displaced people in desperate need has to go hand in hand with offering them a spiritual home. Others see the evangelism of refugees as the proselytisation and exploitation of vulnerable people. So who is right?

In Europe this is a live issue as the continent has a large population of Muslim refugees and asylum seekers within its borders. Germany alone has welcomed around a million refugees in the last nine months. Many of the frontline charities are either explicitly Christian or have a Christian history.

In recent weeks in Germany this dilemma has worked its way out through two very different responses from "evangelical" groups.

The Evangelical Church of the Rhineland included in a 32-page booklet the following statement: "The Great Commission — 'Go therefore and make disciples of all nations, baptising them in the name of the Father and of the Son and of the Holy Spirit' — does not mean Christians must try to convert others to their faith."

This prompted an immediate reaction from the head of the German Evangelical Alliance, Hartmut Steeb: "We declare firmly that the fundamental missionary task of Christians, namely to preach the Gospel of Jesus to others and invite them to follow it, cannot be given up."

So how should Christians working with displaced and vulnerable people understand the sharing of their faith? This is an issue that development charities as well as relief workers wrestle with all the time. There are no simple answers, but there are frameworks for thinking through the issues.

1. Be wary of abusing power

Whenever there are asymmetric power relationships we must tread carefully. Whoever holds that power must be careful not to use it in a manipulative, exploitative or prejudicial way, even for the best of motives.

A police officer cannot apply the law differently if someone they are dealing with is Muslim. A teacher cannot grade children differently because of their religious beliefs. A job interviewer cannot give an applicant an advantage because they are atheist. In the UK and many countries around the world any such prejudicial treatment would transgress equalities and human rights legislation.

In the same way it is best and standard practice in Christian aid and development to offer assistance to people in need irrespective of their religious affiliations, with no strings or conditions regarding attendance at religious meetings and certainly with no expectation or pressure to convert.

However, in all giver-receiver relationships there is an imbalance of power. We should be very careful to recognise the danger that that power may overtly or covertly influence the beliefs of another person.

2. Be wary of being manipulated

The manipulative use of power to coerce people into conversion is not only the antithesis of Christian mission, it is also counterproductive. Adding incentives for people to convert to Christianity in the form of aid has long been known as creating "rice Christians". This was a term that gained popularity in the middle of the 18th century in India where John Henry Grose (1732–1774) of the East India Company used it to criticise the missionary activity of certain priests. Conversions were encouraged, but true motivations were dubious because of the desperate need of the converts to provide for themselves or their families. The "conversions" lasted until the aid was no longer required. Nominal conversions are the natural outworking of manipulative practice. Not only are unhealthy dependencies created but the fundamental teaching of the grace of God is undermined. Bribing people into faith through offering strings-attached aid is not what it means to operate as Christian missionaries.

3. Recognise the myth of ideological neutrality

I was once asked if the charitable efforts of Christians could take place in an ideologically neutral way. But this is a naive request. Every part of our lives is affected by our beliefs about the world. The language we use, the food we eat, the clothes we wear, the books we read are all informed by our views. Whether we are Christian, atheist or have no defined religious persuasion, our beliefs shape who we are and how we relate to others.

Because we are human beings, not automata, we bring our whole selves to the work that we do. For example, I am male, Asian, and Christian and I cannot switch off any of these identities when I engage in the world. These elements of my personhood inform so much of what I do, say and think. To be asked to hide any of these elements from my public life would seem to be a form of censorship, racism or sexism. But if I were to assert that being male, Asian or Christian was somehow superior to other identities, I could rightly be accused of being racist, chauvinist or imperialistic.

In an aid and development context, to actively promote any of these identities may be unhelpful. However, there is an important difference between promotion and affirmation. Aid workers should not feel the necessity to suppress their Christian identity any more than they should feel the need to hide their race or gender.

4. Relationships are essential

Someone who has been displaced because of war, bereaved through terror or personally abused needs more than food, shelter and medical attention. Compassion, respect and comfort are best expressed not through a cold, formal system but through authentic relationships. Genuine relationships are not paternalistic, where one person simply pities or condescends another, but mutual, with a clear sense of give and take, openness and respect.

Should aid workers develop relationships with those that they seek to serve and help? Of course. But there have to be professional guidelines and limits in these relationships. For example, reports of sexual abuse perpetrated by UN peacekeepers in Central African Republic are a clear violation of appropriate relational contact. But the right to engage in the mutual exchange of ideas in respectful and robust dialogue is a valuable aspect of relationship building that needs to be upheld and protected.

5. Acknowledge all communication is persuasion

Whether we mean it or not, every form of communication is an attempt to influence or persuade another person. Each question we ask seeks to persuade someone to disclose some information or to change their thinking on something. Each declaration we make is an attempt to persuade our listener that what we are saying is true and worth listening to. Each opinion we offer will have some impact on those around us. Each gift we present, helping hand we offer, eye contact we make draws others into relationship. It is virtually impossible to engage with refugees in a way that does not try to influence them. Although the Bible is very clear that we have an obligation to honour and respect everyone regardless of their religious affiliation, the fact that Christians believe that faith is true and helpful will necessarily be communicated at some level. And because it is communicated, there will be an element of persuasion. But where persuasion becomes coercion or manipulation, a line has been crossed.

When I visited Lebanon, most of the volunteers I came across visiting refugees were Christians. They came to listen, to bring food, clothes, and medical supplies. I witnessed a few friendly conversations where Muslim refugees asked questions about the motivations behind Christians coming to visit them. I witnessed genuine relationships, laughs and smiles as friends from different countries and religious traditions built bridges.

I saw a church that had repurposed its building to be able to provide a space for hundreds of refugee children to receive three hours of schooling every day because no one else was willing to take the initiative. I met Muslims who had made informed decisions to become Christians because they had seen the hospitality and generosity of Lebanese Christians. For them it was a matter of exercising their freedom of religion to choose to convert to Christianity. I believe it is possible to share faith in appropriate, non-exploitative ways that demonstrate respect and honour to those with whom we communicate.

Rev Dr Krish Kandiah is the founding director of Home for Good and an author and speaker. Follow him on Twitter @krishk