The Church is the “community of all true believers for all time” (Grudem). It is the people of God, formed by God for the purposes of God for the glory of God. The origin of the church lies within the redemptive and creative purposes of God. In the OT, God called Israel to be a people who would bring glory to His name, hold to His laws, offer pleasing worship, and be a light to the nations. When Jesus—the true Israel—came to earth, he founded the church by calling and choosing 12 disciples/apostles. These apostles—by the power and leading of the Holy Spirit—proclaimed the gospel and God added to their numbers. The church is the continuation of Israel and is the true people of God today (Gal 6:16). Other important images which describe the church are the body of Christ (Rom 7:4; 1 Cor 12:27), the bride of Christ (Rev 19:7), and the household of God “a pillar and buttress of truth” (1 Tim 3:15).
The church’s role is to proclaim the gospel and make disciples (Matt 28:18-20). She functions much like a tank and a hospital (R.C. Sproul). As a hospital, she cares for her members, applies the soothing comforts of the gospel, helps members grow in knowledge and love of God, equips believers for ministry, and protects them from wolves and false teachers. As a tank, she brings the message of the gospel to the world through love and proclamation–performing works of mercy in the world and evangelizing to the lost, advancing the kingdom of light in the kingdom of darkness.
The church differs from a mere earthly organization in many ways. First, her head is Jesus, who rules the church from heaven (Col 1:18). Second, she exists invisibly among the visible. Third, she is ruled by the Scriptures rather than earthly principles and practices and led by the Holy Spirit. Fourth, she exists to bring glory to God rather than glory to self. Fifth, she freely gives away her product (the gospel), rather than laboring for earthly profits.