The marks of a true church must be tested finally against the teaching of Scripture, which is the sure instruction of the Apostles and the inerrant Word of God. Protestants have traditionally agreed on two marks: the right preaching of the Word and the right administration of the sacraments. Many list church discipline as a third mark of the church. Others make it part of the right administration of the sacraments, as discipline determines who may receive these means of grace.
The right preaching of God’s Word is an obvious mark of the church. Without faithfulness to the foundation of Christian belief, no group can rightly call itself Christian, let alone a church. Summaries of the essential teaching of Scripture such as the Nicene Creed and Westminster Confession of Faith can assist us in determining whether a particular church accurately preaches the Word. Sacraments are visible words of God, so their right administration also marks a true church. Today’s passage proves that the earliest Christians affirmed these two marks of the church, for the first New Testament church devoted itself to Apostolic teaching and the breaking of bread (the Lord’s Supper) (Acts 2:42). Word and sacrament, rightly administered, were the emphasis of the Apostolic church, and so they must be our emphasis today.
True churches are identified by their faithfulness to the Word of God, not by their size or influence in the community. A church that hears and obeys Scripture cannot help but reach out to the society around it, but the mere presence of programs or a gathering of professing believers does not necessarily mean a church is present. As believers, let us call our churches to remain faithful to God’s Word and to administer the sacraments rightly and regularly.