The biblical doctrine of the church can be found summarized in the Nicene Creed, which confesses belief in “one, holy, catholic, and apostolic church.” Our focus thus far in our study of the church has been on its oneness — its unity — and we have seen that the church cannot be truly one unless it is united in the truth. Though it is regrettable that the church as a visible body is currently far from unified, we do recognize that Christians share a profound, invisible unity in Christ when they hold to the faith once delivered to the saints (John 17; Gal. 3:28). All who believe the Gospel are one in Christ Jesus the Lord.
Holiness is the second attribute of the church defined in the Nicene Creed. Of course, we must honestly admit that the church at various times in history has appeared far from holy. Too often we hear stories of church members acting no differently than the world around them, even indulging in the vilest of behaviors. To be sure, not every church member is actually a believer, and professed Christians who sin boldly without repentance are not Christians at all (James 2:26). Nevertheless, regenerate people sometimes commit heinous sins (Mark 14:66–72); thus, it is difficult to think of the corporate body as holy.
Looking at the Greek word that we translate into the English as “church” will help us understand what the holiness of the church really means. This term, ekklesia, literally means “the called out ones.” The church’s holiness lies in its being separated from the world, called by God to be a unique people whose vocation is to serve Him (1 Peter 2:9–10). Our Creator has made the church uncommon, a body set apart to live differently than the world.
That Christians often fail in this vocation does not make their calling any less real. Positionally speaking, in Christ the church is always set apart as holy (1 Cor. 1:2). But the reality of this holiness in practice is something after which the church is always striving. God has declared us holy in His Son (we are “saints,” Eph. 1:1), and now, by the power of His Spirit, He is making us holy so that one day we might be without spot or wrinkle (5:25–27). Those called by the Spirit pursue sanctity, endeavoring to live up to the high calling of holiness.
The holiness of the church universal should make us take our membership in local congregations seriously. Were we to be convinced of the church’s holiness, we would not casually drift from one denomination to another. We would understand that to leave a church for reasons other than doctrine, distance, or to accept a call to service manifests a questioning of that church’s holiness, which is something we must not do lightly if God has said His church is holy.