We believe Jesus wants His followers to work together as a family.
Jesus did many things that were almost unthinkable to the people of His day. He touched lepers, treated women as equals, and praised Romans. But possibly the most unthinkable thing was to talk about God, the almighty creator of the universe, as His Father.
This was the core of His belief, the conviction that powered His life. He knew that God, His Heavenly Father, loved Him, and He taught how His followers could also know that they, too, were loved and accepted as His children.
So, at the centre of His teaching and ministry, Jesus was creating a family. He was not setting up an organisation, but establishing a family, a group of people who are bound together because they are all brothers and sisters, all children of the same Father.
It is the nature of families to argue and fight, but these disagreements do not mean you are no longer part of the same family. Sometimes one part of the family is so hurt by another part they refuse even to talk. Sadly, this has happened too in God's family. But none of the arguments between those who follow Jesus can affect the basic reality - we are all one family, and our Father commands us to love one another, no matter how hard this may seem.
There is plenty of work left for Jesus' followers to do - we are commanded to take the good news of our Father's love to the people in every nation. We are to pray and work for our Father's Kingdom to be established on the Earth. But He wants us to do all this together - helping each other, as members of a family should. Neither Jesus not the people who came after Him expected us to be able to do it any other way.
A Kingdom of love can only be built by people who are prepared to love, no matter what. That is what being part of God's family is all about.
There are many Christian jokes. One of the standard ones is a description of Heaven: a newcomer is shown around and finds the Quakers not talking, the Pentecostals shouting to their hearts' content, and so on... a variety of denominations, all with their distinctive ways. And finally, they come to a high wall, and hear people singing songs behind it. "Who is behind the wall?" they ask, and are told, "That's the ..." [insert the denomination of your choice] "- they think they are the only ones here."
Of course, in Heaven we will not be able to avoid the reality of sharing eternity with all the saved, from all of history.
More importantly, down here on Earth, while the denominations have largely failed to recognise and work together (at least, until recently), individual Christians have often managed to get together and work on all kinds on useful tasks. Once we stop arguing about theology, Christians have an excellent track record in working together and functioning as the single family we believe ourselves to be.
What about all those Christian cults we hear about?
The idea that Christians are called to work together as a family is so deeply fixed that it makes an excellent test for deciding who are the Christians and who are the pseudo-Christian cults.
With all the different groups and denominations, it is hard for the outsider to work out what is going on in the Christian Church, or even who is really part of the Church. After all, they all seem to disagree with each other about so much.
So the simple test is this: if the group recognises the members of the other traditional Christian denominations as being fellow Christians - members of the same family - then they are themselves part of the Christian family. If they don't, then they are not.
So, for example, my Catholic friends recognise that I am a Christian and a fellow believer, even if I am sadly separated from the 'one true church'. But members of the Church of the Latter Day Saints - Mormons - do not recognise me as a fellow believer: as far as they are concerned, I need to join their group in order to be saved. So Catholics form a part of the wider Christian family, while Mormons do not.
The alternative, to be frank, is what most of the Christian Church has been doing for most of the last two thousand years: not working together as a family.
But, as I point out above, not acting as a family does not mean that we are not a family.