Although attendance at different churches can give someone a taste of the good, the bad and the ugly of church life, it is not a pattern found in the Bible. On the contrary, the biblical assumption is that Christians will be active members of one local church, which functions like a family, submitting to godly shepherds who care for them as part of ‘the flock, among which the Holy Spirit has made you overseers’ (Acts 20:28).
The language we use to speak of the local church is important. We may speak of a church as ‘a fellowship’ of which we are members. Although ‘fellowship’ and ‘church’ are used interchangeably today, they are not synonyms. The Greek word koinonia, often translated ‘fellowship’, refers to a mutual sharing or common interest in something. It is used of sharing a truth or a burden, a common bond, joy, provision or responsibility. Christians in a church are expected to express fellowship in many ways.
The Greek word translated ‘church’ in the New Testament is ekklesia, which most scholars agree means a group of people ‘called out to gather together’. When used of Christians, it carries the thought of intentional, active participation. Paul used this word to address companies of Christians at Corinth, Ephesus, Antioch, Jerusalem, Philippi, Colossae and other places. This is not the same as membership of a gym or a club, which you don’t use for months. Being a member of a church in a locality, is to be actively in fellowship with other Christians, who have also been called out of the world to gather to the name of the Lord Jesus Christ.
Paul also used the word ‘church’ in a slightly difference sense, to refer to all Christians from the time the Holy Spirit descended at Pentecost (Acts 2:1-47), to the time when the Lord will return to the air for His people (1 Thessalonians 4:13-18). This is what Paul referred to when he spoke of the church which is Christ’s body (Ephesians 1:23).
"This is not the same as membership of a gym or a club which you don’t use for months."
There are significant differences between these two usages of ‘church’. When people are saved, they immediately become part of the church which is the body of Christ. Paul speaks of them as members of that one body: ‘in one Spirit we were all baptized into one body—Jews or Greeks, slaves or free—and all were made to drink of one Spirit’ (1 Corinthians 12:13). For this church, no application process is required, nor is there any possibility of being removed from membership. Neither baptism, nor any other spiritual exercise or qualification, brings admission into this church – only new birth.
By contrast, no Christian automatically or immediately becomes joined to a local church at the moment of conversion. Furthermore, it is possible to be removed from a local church. For example, Paul had to make the effort to join himself to the Jerusalem Christians (Acts 9:26), and later wrote to the church at Corinth with instructions to put away from the church a man who was practising gross sin (1 Corinthians 5).
Every genuine Christian is part of ‘the church which is his body’ (Ephesians 1:22-23), and every Christian should also be part of a local church.