Thankfully, even though the church as a visible body is fragmented and divided, God is still answering Christ’s prayer for His church to be one. As all believers in the gospel recognize, Christians share a deep and profound unity in Christ as they hold fast to His truth (John 17; Gal. 3:28). Today this unity may be largely invisible, but it is a true unity, an actual oneness grounded in the gospel of God. Another important attribute of the church is its holiness. Yet this may be the attribute that is most difficult for us to see. Throughout history, the church has not always followed God’s will when interacting with its own members and the larger culture. Moreover, we know from observing our own actions and the behavior of those around us that sin continues to plague the people of God. At times, we even see professing Christians doing the vilest things. Certainly, not every member of the visible church is regenerate, and ultimately, professing believers who remain impenitent prove that they are not in Christ at all (Rom. 9:6; James 2:26). That truth, however, does not change the fact that even regenerate people can commit heinous sins (2 Sam. 11:1–12:23; Mark 14:66–72), which can make it hard for us to see the corporate church as holy before the Lord. Understanding the meaning of the term holiness can help us know what it means that the church is holy. As we have noted in other studies, the biblical concept of holiness has chiefly to do with being set apart unto God. The concept of moral purity is not unrelated to holiness, but that has to do more with putting holiness into practice than with how God regards His people as sanctified in Christ. As holy, the church is set apart from the world to serve the Lord (1 Peter 2:9–10). Our Creator regards the church as holy because He has set it apart from what is common. Even when the church does not act in a holy manner, the people of God are still regarded as holy because God has declared us holy in His Son. (We are “saints”; see Eph. 1:1.) Living in a holy manner as a corporate body is not what makes us holy in God’s eyes, although it confirms our profession to the world. The church is holy because it is in Christ (2 Tim. 1:8–9), and through faith and repentance we seek to be in practice what God says that we are positionally in His Son (Rom. 6:1–4).