Why do Christians meet up so frequently for church? I mean let us be honest, that is quite a commitment Christians make on a weekly basis. Every week, Christians give up several hours of their time to meet up with other Christians to do “church”. Why? Is there any significance to this? I mean, the Bible says that since I am a believer, my body is a holy temple designed for the Lord to dwell,  so why can I not do church on my own? As Christians, it is crucial that we understand not only why we must meet on a weekly basis, but why we must meet period.
The Church Gathers Weekly Because of its’ Roots
Before the coming of Jesus Christ, followers of God were bound to the laws of the Old Testament. One of the laws that had to be kept was, “Remember the Sabbath day, to keep it holy.”  The Sabbath day always fell on the seventh day of the week, Saturday. On this day, Jews would gather and worship God by offering sacrifices for the payment of their sins. In the first century when the Christian church was being born, Christians switched their day of worship to the first day of the week because Jesus Christ rose from the grave on the first day of the week, Sunday. In places such as Acts 20:7 we read examples of the church gathering on the first day of the week. This is why Christians today have corporate worship every week on Sunday because with Christ’s resurrection came a new day to celebrate and worship with our eternal payment resting in him. This, however, is not the only reason for the purpose of the church’s weekly gathering.
The Church’s Gathering Demonstrates Our Unity in Christ
Nowhere in the Bible will you ever encounter Christians being described as merely isolated individuals. The only people that the Bible deems “isolated” are those who are enslaved to their sin and do not have a relationship with God almighty. In fact, the Bible describes these people as being “strangers and aliens”.  Rather, the Bible describes Christians as being a corporate body of many people because we are all united in Christ through faith. In Ephesians 2:19-22, Paul says to the church of Ephesus, “So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure, being joined together, grows into a holy temple in the Lord. In him you also are being built together into a dwelling place for God by the Spirit.” 
It is only through Jesus Christ that we can have a relationship of eternal and perfect unity with God and with each other. The reason why Christianity has a corporate nature is because of our unity in Christ, and this is why the church exists. In 1 Corinthians 12:27 Paul says to the church of Corinth, “Now you are the body of Christ and individually members of it.”  When Christians go to church, they are making a resounding statement that because Jesus Christ died to create a unified people, we are no longer isolated individuals for the rest of eternity. So, the church is the gathered assembly of Christians with the intention to express unity in Jesus and to worship together.
The Church Gathers to Build One Another Up in Christ
Because of our unity in Christ, the purpose of gathering weekly for church is also meant for Christians to build each other up in Christlikeness by worshipping God together.  The New Testament explicitly emphasizes the importance of Christians gathering together for the sake of building one another up to become more and more like Christ.
In 1 Corinthians, Paul emphatically explains to the church of Corinth that edification, the building up of other believers, is what matters most.  Paul says that Christians are to “strive to excel in building up the church.”  Later on, Paul stresses again the guiding rule that everything within the church is to be done for the sake of building one another up, “What then, brothers? When you come together. . . Let all things be done for building up.” 
We see Paul discuss this idea of “building each other up” in his letters to other churches. In his letter to the Ephesians, Paul says that the church is to be“…addressing one another in psalms and hymns and spiritual songs, singing and making melody to the Lord with your heart, giving thanks always and for everything to God the Father in the name of our Lord Jesus Christ, submitting to one another out of reverence for Christ.” 
Likewise, in his letter to the church of Colossae Paul writes, “And let the peace of Christ rule in your hearts, to which indeed you were called in one body. And be thankful. Let the word of Christ dwell in you richly, teaching and admonishing one another in all wisdom, singing psalms and hymns and spiritual songs, with thankfulness in your hearts to God. And whatever you do, in word or deed, do everything in the name of the Lord Jesus, giving thanks to God the Father through him.” In three separate occasions Paul makes a definitive point that one of the fundamental reasons Christians meet together for church is for the purpose of building each other up in holiness.
The Church Gathers Because Christ is the Goal
How then do Christians edify one other in church? Edification in corporate gatherings must be centered around God and his Word. The church is instructed in God’s Word to gather to hear the Word,  preach the Word,  pray the Word,  sing the Word,  and see the Word in the Lord’s Supper and baptism.  When the church is “tethered to and drawing sustenance from the true vine (John 15),”  then the corporate body is being built up in love, and since Christ is the goal, we continue to meet up on a weekly basis “until we all attain to the unity of the faith and of the knowledge of the Son of God.” 
Jamieson, Bobby. “What Is Corporate Worship For?” 9marks, 21 August 2014. https://www.9marks.org/article/what-is-corporate-worship-for/.
Johnson, Tiffany. “Why Should I Go to Church?” Desiring God, 28 October 2017. https://www.desiringgod.org/articles/why-should-i-go-to-church.
Morris, Leon. 1 Corinthians: An Introduction and Commentary, vol. 7, Tyndale New Testament Commentaries (Downers Grove, IL: InterVarsity Press, 1985), 186.
Piper, John, and Tony Reinke. “Why Do Christians Worship Together on Sundays?” Ask Pastor John, n.d. https://www.desiringgod.org/interviews/why-do-christians-worship-together-on-sundays.
The Holy Bible: English Standard Version (Wheaton,
IL: Crossway Bibles, 2016).
 Ex 20:8
 John Piper and Tony Reinke, “Why Do Christians Worship Together on Sundays?,” Ask Pastor John, n.d., https://www.desiringgod.org/interviews/why-do-christians-worship-together-on-sundays.
 Eph 2:19.
 Eph 2:19–22.
 1 Co 12:27.
 Bobby Jamieson, “What Is Corporate Worship For?,” 9marks, 21 August 2014, https://www.9marks.org/article/what-is-corporate-worship-for/.
 1 Co 14:12.
 1 Co 14:26.
 Eph 5:18–21.
 Col 3:15–17.
 1 Tim 4:13.
 2 Tim 4:2.
 1 Tim 2:1, 8.
 Col 3:16.
 1 Co 11:17-34.
 Tiffany Johnson, “Why Should I Go to Church?,” Desiring God, 28 October 2017, https://www.desiringgod.org/articles/why-should-i-go-to-church.
 Eph 4:13.