The church Jesus left behind in Jerusalem and the church we experience today couldn't be more different, not only in terms of numbers, but also in practices. It didn't take long before the first simple disagreements and then power struggles, both internal and external, began to dominate church history.
If there is a word that could characterize the first church as Luke describes it in Acts 2 and 4 I would say it is unity. In the beginning there was no distinction between church and society. It was all one and the same to them. There was some resistance from other Jews, but internally, they seem to have been pretty united in fellowship and devotion to one another.
Soon after, however, divisions entered the picture. For example, the Council of Jerusalem was called in AD50 to settle various disputes between the Jewish Christians and the Gentile Christians, but that wasn't all. Soon all sorts of disputes about theological details started to pop up.
As their numbers grew, tensions with the outside world also increased. In response, the Romans turned up the persecution. Christians in Rome had to walk a pretty tight line to stay alive. As their numbers grew, their influence also grew and made it harder for the Romans to keep them oppressed and in AD313 the persecutions ended with the edict of Milan setting the stage for a dramatic turnaround in the lives of Christians everywhere. With their newly acquired acceptance, access to political power and to wealth quickly became dominant drivers. As the church in Rome gained power, the eastern church fragmented into various metropolitan centers throughout the region. The church in Rome continues to influence life in the west to this day.
Stoning has never been an accepted practice among Christians, but that didn't stop church leaders from executing opponents by burning them to death. Lots of kings and emperors have been crowned by Bishops. "Discoverers" have exploited indigenous populations around the world with the express blessing if not encouragement of the church. Countless wars have been fought in the name of Christ.
In the modern church, divisions are the norm. Dozens of labels separate us into groups with different opinions and the opinions aren't just in the details. Some of them are pretty fundamental. The division reflects the separation in the world around us. To unite us, Jesus told us to love God, but that doesn't really work when people can't agree on who God is or what it means to love God.
As a result of the fragmentation, you as a church member, can basically spend your entire life surrounded by people with blinders firmly in place to tune out any outside influences. All you would need to know is that those other people aren't our people. They are not like us.
A quick look at the world's distribution of wealth makes it clear to me that one of the obstacles to unity is our insatiable thirst for hoarding things at the expense of others. If the world's riches were to be distributed equally, I'm sure there would be plenty for everyone. The ancient writers' vision for a Garden of Eden is possible. Jesus' message is to repent and be baptized. That is simply old language for organize, unite and change direction.
Turn from unbridled consumption to caring for our brothers and sisters around the world who suffer through poverty and violence.