The vast majority of modern churches would look far different today if the Biblical model described were adhered to today. Learning objectives would be clearly defined and people with the appropriate gifts selected for carrying out discipleship ministry. That is not to say that other ministries that are not directly related to discipleship are not an important part of the functioning of the local church. The various parts of the body of Christ have different functions and should be used accordingly. It is unlikely that most churches would have their musicians on their finance committees. It is also equally unlikely that those churches would want their finance committees performing the Sunday morning music (of course exceptions exist!).
With clearly defined goals of discipleship there should also be the clear explanation that there are expectations of Christian service which include sharing our faith. The apostles were called by Jesus with the clear expectation that they would one day go into the world and preach the gospel. Christians are expected to become more like Christ and to share the good news with others. This should not be taken to mean that every Christian will be called to the pulpit but it does mean that every Christian should be sharing their faith.
There is also the matter of purity that is expected by God of His people. The church would do well to refrain from calling everyone a Christian that calls on the name of Jesus. Matthew 7:16 tells us that we will know them by their fruits. Perhaps saying so should happen more often. A few verses later we are also told that not everyone who says “Lord, Lord” will enter into heaven (Matt. 7:21). The church should boldly be concerned with purity and go about the business of making disciples who are prepared to go into the world and proclaim Jesus. In summary, the model I believe should be followed is one that prepares and maintains an environment where discipleship can take place, identifies those from among the body available for service, equips those saints for service, and sends them out where they can provide a blameless testimony for the salvation freely offered through faith in Jesus Christ.