Pastors and parishioners perennially battle over who has authority in matters of church practice, particularly in corporate worship. Should what happens in the corporate gatherings of God's people fall under the control of church leadership, or should these decisions be left to congregational input and direction? If the former, are pastors to be guided by particular traditions and directories, or may they choose whatever they believe to facilitate goals toward which their congregation assembles? If the latter, are these matters to be given over to a vote, or will a representative committee suffice?
Each of these potential solutions falls short since the Word of God itself provides all that is necessary for the regulation of corporate worship. This regulative principle of worship very simply states that churches may include in their worship only that which Scripture explicitly prescribes or what may be reasonably deduced from Scriptural principles and examples. Conversely, churches may not include in their worship anything that the Bible does not command. Put simply, whatever is not prescribed is forbidden. Thus is it not left to either church leadership or church members to decide how they will worship; biblical worship must finds its justification in Scripture alone.
This principle is based on three key biblical principles:
First, God alone has the prerogative to determine how he is to be worshiped. The purpose of corporate worship is not primarily evangelism, edification, or entertainment. Although, with the exception of entertainment, these things do take place in corporate gatherings of the church, their primary purpose is to draw near to God through Christ by faith on his terms. Thus how that looks should be firmly rooted in what God has commanded.
Second, Scripture is full of examples of God rejecting worship that includes elements that he has not prescribed, even if the worshipers have right motivation. Whether with the golden calf (Deut 9:16), Nadab and Abihu (Lev 10:1-3), or the Pharisees (Matt 15:8-9), God does not approve of worship practices that he himself has not sanctioned.
Third, Scripture is clear that Christians have liberty of conscience in spiritual matters. In other words, no Christian may be expected to participate in a spiritual practice that he is not "convinced in his own mind" is necessary (Rom 14:5-6). This limits even pastoral authority. No pastor or other church leader has the authority to impose upon another a spiritual practice—no matter how it has "an appearance of wisdom" (Col 2:20-23)—that does not have explicit biblical warrant.
This principle, far from being restrictive, is actually quite liberating. Pastors do not need to worry about chasing after the latest popular worship fads or conducting preference polls of their people. Likewise, church members need not fear the next worship novelty, nor will they need to deliberate over what best worship practices they should adopt. The church simply follows the clear instructions of Scripture.
On might object that Scripture really doesn't prescribe all that much for corporate worship, and therefor a church cannot be expected to limit its practice only to what God has commanded in his Word. Yet this objection begs the question. Perhaps the very simplicity of biblical commands regarding corporate worship demands simple, un-adorned corporate worship characterized by Scripture, song, prayer, preaching, giving, baptism, and the Lord's Table.