People usually think that church refers to a religious building. However, if you look at the Greek word for church, ekklesia, it actually means “called out ones” or “an assembly of people.” In the New Testament, the first mention of “church” is found in (Matthew 16:18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.), after Peter’s confession about the real identity of Jesus as the Son of God. You can also find another instance in Matthew 18:15-20, where Jesus talked about reprimanding a brother or sister in church who stubbornly sins. Here, you will find that Jesus talks about the church as a congregation, not a building. Paul also referred to the church as a gathering within a house (building) in (Romans 16:5 Likewise greet the church that is in their house. Salute my well-beloved Epaenetus, who is the firstfruits of Achaia unto Christ.). Conclusively, the term “church” refers to people, not a building.
The foundation of the church is Jesus, not Peter or any other early Christian leaders. In Matthew 16:18, Jesus said to Peter, “Thou art Peter, and upon this rock I will build my church.” Peter’s name is from the Greek word petrus, which means small rock, and when Jesus said “and upon this rock,” He was referring to Himself, not Peter. Because the rock in the scripture above is a different Greek word, petra, which means big rock or bedrock. Though the work of leading the church had been entrusted to the Apostles, Jesus is the chief cornerstone of His church (Ephesians 2:20-22). Also, if you read further to Matthew 16:19, Jesus said that He was giving the keys of heaven to Peter. This does not mean literal keys to heaven over which Peter was given authority. It is merely figurative, referencing the work that Peter would be doing later, opening the opportunity for salvation to Gentiles.
It is within Christ’s church that you will find meaningful and lifelong friendships, what we call a spiritual family. There is fellowship available for every believer to encourage, comfort, correct, and learn from each other in a church community (Acts 2:42,44-46). In church, believers express their love, devotion, and commitment to God through worship (John 4:23,24), but church is not exclusively for believers. It is also meant to engage, evangelize, and welcome the lost. It is called to grow as many more lost souls are added to the family of God (Acts 2:47 Praising God, and having favour with all the people. And the Lord added to the church daily such as should be saved.).
Since Christ is the head and the church is the body of Christ (1 Corinthians 12:14-27), all Christians are called to be united against the forces of darkness. The greatest damage to the church does not come from outside threats (persecution, calamity, financial lack, and the likes), but from the inside (gossip, squabbling, false teaching). That is why the church community has been exhorted to love one another (John 13:34 A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another.), forgive and bear with each other (Colossians 3:13-14), and to make every effort to maintain unity (Ephesians 4:3). Jesus described the church as a victorious church, one that could prevail over the gates of hell (Matthew 16:18). That is Christ’s unfailing promise and our battle cry every time the church runs up against the darkness of this world.