Top Roman Catholic ecclesiastics have spoken out against using charitable work as a 'front' for evangelism. A Vatican conference has heard warnings against trying to manipulate people into conversion through doing good things for them.

Instead, as Cardinal Antonio Tagle from the Philippines said: "The Christian truth is beautiful, and beautiful things attract." 

Many churches do undertake charitable or social action projects, ranging from toddler groups to debt counselling or domestic violence support. But in a multi-faith society and a complicated world, Christians are having to navigate increasingly complex issues around evangelism. One of these is about how it relates to social action. At its starkest, the question looks like this: should we do something good just because it's good, or should we do it hoping to convert people?

One side argues like this. Christians are supposed to reflect Christ in all they do. Jesus didn't heal the sick in order to persuade them that following him was a good idea; he healed them because they were sick.

We should do good just because it's good. If we don't, we're attaching conditions to the gospel and risking people being drawn to it just because of what they can get out of it. The label for converts like this is "rice Christians", defined in Brewer's Dictionary of Phrase and Fable (1898) as "Converts to Christianity for worldly benefits, such as a supply of rice to Indians" – someone's starving, and you offer them food if they convert, which is clearly wrong. So you should provide a church's play group or dementia care group just because it's needed, not because you want to make converts because of it.

The other side argues like this. Evangelism is paramount. Jesus told his disciples to go into all the world and preach the gospel. He wants all the world to repent and trust in him. Everything a church does should be geared to making and discipling converts. If we don't have that as our goal, we're betraying his commands. Churches that set up youth groups or day centres and don't mention Christ are just acting as social services instead of fulfilling their God-given mandate to make disciples. A debt counselling charity that doesn't present the gospel is a waste of time.

Now, those are the extremes. Most people reading this will fall somewhere in the middle of the spectrum between them. We believe Christians should always do good ("Therefore, as we have opportunity, let us do good to all people, especially to those who belong to the family of believers," says Paul in Galatians 6:10). But we believe, too, that Christians should never forget they're called to witness to Christ. In everything we do, we need to be transparent about why we're doing it and never compromise on our identity as Christians.

How we do our social action might look different in different contexts. A contribution from the Theos theological think-tank last year put it like this. The Problem of Proselytism looked at faith-based organisations involved in social welfare. It helpfully distinguishes between the "full-fat" approach, where organisations major on faith and the transformation of individuals; the "half-fat", where services are linked to a worshipping community and "holistic" mission is practised; and "low-fat", where organisations "disavow proselytism or overt evangelism as such", but see users as being on a "spiritual journey". It doesn't say one approach is better than another, but stresses that faith-based organisations should be "intentional, honest, explicit and consistent in their approach, rooted in a clear understanding of what they are trying to achieve".

Most churches and faith-based organisations will fall into one of those categories. Whichever one describes our own, here are principles for how we do good and evangelise at the same time.

1. Honesty

We should never put on a particular event or offer a service pretending it's one thing when it's another. If a university Christian Union offers new students free food, they should be clear if it's going to include a talk about Jesus too.

2. Respect

Speaking at the Vatican conference last week, another German cardinal gave the example of Christians helping Muslim refugees in his country. Cardinal Gerhard Muller said: "We must not use the charity we practise and transform it into an instrument of proselytism."

Sometimes, he said, "a silent witness is the best witness of the love of God". But, he added: "There are among these migrants, the majority of whom are Muslim, [some] who ask, 'Why are Christians, and not our fellow Muslims, helping us?'"

And when those questions arise, he said, aid workers shouldn't be afraid to give an answer "rooted in the faith".

3. Integrity

If we're Christians, we have to be absolutely clear about our identity as disciples of Christ. Whenever we're in a situation of engaging with people who don't share our faith, we need to be ready to bear witness when we can. This isn't the same as trying to shoe-horn references to Jesus into every conversation: as 1 Peter 3: 16-16 says, "Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect, keeping a clear conscience, so that those who speak maliciously against your good behaviour in Christ may be ashamed of their slander."

4. Compassion

Some needs are visible, others aren't. If someone has a problem with alcohol or other drugs, is homeless or in debt, it may be easy to see their need. But everyone needs a Saviour, too, whether they know it or not. True compassion addresses people's spiritual needs, not just their other needs.

One thing the Bible is very clear about is this: not doing good to people who need it is not an option. In a solemn warning, Jesus uses the image of a shepherd separating sheep and goats (Matthew 25: 31-46). The King tells the "goats": "Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. For I was hungry and you gave me nothing to eat, I was thirsty and you gave me nothing to drink, I was a stranger and you did not invite me in, I needed clothes and you did not clothe me, I was ill and in prison and you did not look after me."

We all know we should be doing good to our neighbour. We all know we should be preaching the gospel, too. Maybe the most important thing is finding the right balance so we can keep both of Jesus' commands and bring the whole gospel to the whole world.