The word "church" has two main meanings. The Church (often with a capital C) can be used as a collective noun referring to all who follow Jesus Christ, but the word "church" normally refers to a building for public Christian worship. On this page I will be explaining the latter - why we have churches and what happens in them.
Christians go to church primarily to worship God, but it is a valid question to ask "why have churches if God is everywhere?" Well, church is a place where Christians can gather together and read the Bible together, pray together, and learn together. You can do all these things by yourself, but the key word here is "together". There are many cases in the Bible of people coming together to worship, for example at the Last Supper.
Jesus himself went to temples and synagogues from an early age (Luke 2:46) and taught in them (Luke 19:47), reading from the Scriptures. He exaplined how the Temple (the place of worship before churches) was a very holy place and he got very angry when people used it inappropriately (Luke 19:46). He explained that the Temple was God's House and deserved respect. It is a sacred place where God resides. Jesus would not have made an effort to tell people this if holy buildings were not an important part of worship.
Following Jesus' death and resurrection, early followers of Christ would meet up and worship together. This soon became standard and churches were built. Coming together to worship is very important in developing as a Christian but the types of church and their services can vary immensely.
Although the message of God given to us through the Bible applies equally for everyone, we're all different and like different things. It's the same when it comes to worship and hearing the gospel. A good church should teach who God is and what He has promised us as well as making good use of the Bible, but how it does that can vary greatly. While some people like solemn, quiet worship, others like to get excited and jump around, but most people would say they fall somewhere between these two extremes. To match the fact that people differ greatly, so do churches.
These subdivisions of Christian worship are called "denominations". Broadly the main denominations are Catholic, Protestant and Orthodox but these are then further divided - for example Protestants can be Anglican, Baptist or Methodist, to name a few. Sometimes people can be too obsessed by denomination and miss the point that Jesus came to save us! It is extremely important to look beyond the idea of a denomination, or a preferred style of worship, and grasp the message of the gospel, the heart of the Christian faith.
Churches can be very small buildings (chapels) or much larger structures (cathedrals), or anywhere in between. How they are furnished depends largely on the denomination, age of the building and personal choice of those who maintain the church. Most churches have rows of seats or pews facing the front for the congregation (the people who attend church) to sit during a service. At the front, the priest (vicar or minister) stands and delivers services. The priest will likely also have a table, lectern (where s/he reads from) and a font or baptistry for baptisms. There may be other rooms within the church for the priest to prepare in and for recreational purposes, amongst other things.
Very many people have never been inside a church before, or if they have it's only been for special services like weddings. But there is so much more to church and what happens can vary immensely! No matter who you are and what you believe, you should always find yourself welcome in church.
Most of the time a church is used on Sundays for services (often at least one in the morning and one in the evening). What happens during a service varies depending on the church and its denomination, but typically the congregation will sit down to listen to the priest (vicar or minister) who stands at the front. Since church is a place to worship and come to understand God, it only makes sense that prayers will be said. These may be by the priest, someone else, or the congregation as a whole (read off a sheet or screen).
In some services songs are sung. These can be hymns sung to a traditional organ, or more modern songs of worship, often with a live band at the front. There may be a "collection" where the congregation are free to donate some money discretely for the upkeep of the church. The priest will usually read from the Bible and then explain what the passage is saying and how it applies to our lives. This is called a sermon. Sometimes people will come up and give their testimonies (how they came to be a Christian and how God has changed their life). These people volunteer themselves before the service, so you don't have to worry that they'll pick on you to come up!
Some chuches also perform baptisms during services and many will have some form of Eucharist (also known as Holy Communion or the Breaking of the Bread). This is a simulation of the Last Supper where Jesus gave bread and wine to his disciples as a symbol of his body and blood which he sacrificed so that we might have life after death. He instructed us to copy this symbolic gesture (Luke 22:19).
Other announcements may be made during the service, like highlighting what other events the church is putting on that week. Depending on the service, there may be times when you stand (to sing) and perhaps kneel (to pray). After the service there are often refreshments, or sometimes a whole meal is served and the congregation has the opportunity to socialise. It's all very friendly and informal in most churches, and the church leaders are normally easy to find and talk to if you want to.
Apart from Sunday services, churches do many other things both for Christians and for the wider community. Many offer Bible studies, activities and events for children, and other social events such as holding houseparties (a few days away together). They may also hold courses for non-Christians or new Christians to get to understand Christianity better. Popular examples include "Christianity Explored" and "The Alpha Course".
Churches may also raise money through events like bring and buy sales and this money may go to help those who are in need in the local community. The priest may be able to make home visits for those who are too old or ill to get to church. At special times of year like Christmas and Easter they may do seasonal things like carol singing or Easter egg treasure hunts.
Many churches also have Sunday schools for younger Christians to learn about Jesus together through reading, colouring and making. Churches are often very welcome to suggestions so if you think they are not doing something they could be doing, if you suggest it you may find that your idea catches on and the church will do it! Why not go along to one of your local churches and experience for yourself what a service is like?