We might disagree with atheists' beliefs and reasoning about the Christian faith, but there is a lot to learn from friendships with our unbelieving friends, even the ones who aren't very friendly.
1. What seems obvious to us, does not seem obvious to others
We have to do more than just tell other people what we believe and expect them to believe it too.
If you do not come from a Christian background, adopting the faith involves a huge change of worldview. Without the Holy Spirit it is impossible. But there needs to be a huge change in thinking, too. It can take years to open up minds and hearts to a different way of viewing the world.
On the other hand, atheists who had a Christian upbringing show how important the Holy Spirit is. You may have been taught Christian doctrine from an early age, and even have a Christian worldview, but if you do not know God, then it won't stick. Having a deep and abiding relationship with God is what matters.
2. Church is about God
When the atheist 'church' was set up, its founder said that he got the idea because he went to Hillsong and liked what they did – except the God stuff. So he set up a place to sing songs, meet together with other people and have a talk. When I went to visit this community, though, it seemed dull and empty: the whole point of church was missing. But perhaps some come to Christian churches more to meet friends and have a sing, than to worship God, at least at the beginning. If Jesus left your church, would you notice he had gone?
3. Not everyone wants to know God
I've often asked atheists something along the lines of: if you knew that it is true that God really and truly loves you, that Jesus is real and died for you, would you give your life to God? The answer to this is usually yes, though often with some hesitation. But sometimes they say no. That seems incomprehensible to a Christian, but for some it is their choice at that moment in time.
For those who say yes, we can then wonder, so why don't they believe? There are lots of possible stumbling blocks. Atheists often present rational objections to belief in God. Sometimes they are real and valid, and worth listening to. But often even if they are dealt with, there are other issues underlying these objections, such as lifestyle issues that they feel would be impossible to give up, or pain from suffering that hasn't been healed. But as much as we long that they'd know God's love, it is their choice, and it's important to respect that.
4. Radical love makes the difference
It's fair to say that many atheists live similar lives to many Christians. OK so there's some evidence that on average, Christians are a bit more likely to volunteer their time, donate to charity and suchlike – but you will find plenty of atheists "doing good things" too.
Obviously being a Christian isn't about just doing good works, though they should be a sign of genuine faith. So what's the difference? Atheists often cite this as a reason not to believe.
I think what is rarer outside the church is really radical and extraordinary love that raises eyebrows. For example, missionaries selling their possessions and going out to live among street children in Mozambique; a priest deliberately going to the gas chambers in the place of a man whose name had been called out by the Nazi guards; families who take in hundreds of orphaned children without any pay. There are so many extraordinary stories of great faith and love.
Unusual love can be shown at a more everyday level too. Dan Mohler, a pastor in the US, tells a story about how a car ran into him, but the love he showed to the driver overwhelmed her, because she had expected him to be angry. Can we act in unusual ways too – unusually loving?
To be giving radical love, we need to be in a radical place with God – truly knowing how much he loves us, how much he loves those around us, how trustworthy he is for all the problems of life, and so full of love that when bad things happen, our first reaction is of the Spirit and not of the flesh. This kind of deep faith can and does make a real difference to our lives – we just need to get there!
5. It's annoying to be misunderstood and harangued
If you've had a bad encounter with atheists who seem determined to misrepresent Christianity, twist everything you say, mock you and otherwise be very difficult – it's worth remembering that Christians can be like this too.
Each negative encounter can be lesson on what is annoying, so we can learn to do the opposite and "do unto others as you would have them do to you".
6. How we treat people is important
If you've ever met anyone who cites bad treatment from a Christian as the reason they don't believe, it's a good incentive to pray for more love and kindness, and that we don't inflict our bad moods on others. (Gulp.)
7. Jesus loves everyone
OK so you meet the occasional obnoxious atheist, and sometimes the famous ones can really get under your skin. But does Jesus still love them? Yes. And when Jesus said we should love our enemies and bless those who persecute us – I'm pretty that included a bit of mocking, prejudice, misunderstanding and social ostracising.
Therefore the biggest gift an atheist can give us is to test us on how much we love people who are different to us and who have different beliefs – whether they are being friendly or hostile.