The reformed have a very high view of the church, Saint Cyprian of Carthage famously said that "Outside the Church there is no salvation" and far from abjuring this doctrine Calvin held that "beyond the pale of the Church no forgiveness of sins, no salvation, can be hoped for". While the true church is the body of all believers this spiritual body also has a physical identity. It is through this physical body that the doctrines of the church are protected and taught, it is through this body that the discipline of believers is maintained and believers are discipled. It is through this body that the sacraments of the Church are performed and through which grace is dispensed. Only God knows who are his sheep and the Church contains both regenerate believers and unregenerate hypocrites. Both the regenerate and the unregenerate belong to the church but only the regenerate are justified by the blood of Jesus., Benefits are received by both, the unregenerate come under the preaching of the gospel and receive temporal benefits while the regenerate receive grace and both spiritual and temporal benefits.
It goes against the grain for the western mind to see any importance in anything but a persons individual decision but when Paul spoke to the Philippian jailor he stated that the Jailor should "Believe on the Lord Jesus Christ, and you will be saved, you and your household", the household was "saved", not just the individual. At 2 Peter Chapter 2 the faithful are warned that there will be false prophets who will "bring in destructive heresies, even denying the Master who brought them, bringing upon themselves swift destruction." The physical church contains both the regenerate and the unregenerate.
The key to covenant theology is that the church is not coexistent with Israel or a replacement for Israel, it actually is Israel and the Old Covenant saints are just as much part of the Church as are the saints of the New Covenant. Gentiles were able to join the people of God and those Jews who failed to follow Christ are no longer of Israel. The Jewish nation is no longer Israel in the eyes of God. This stark truth has often been used by fallen man as justification for anti-semitism and this is truly unfortunate, but the truth is the truth and modern day practicing Jews are no worse or indeed no better than the mass of unsaved humanity. The Old Covenant was between God and the descendants of Abraham, the sign of the covenant being circumcision, with the New Covenant being between God and the spiritual children of Abraham who are united to God through Jesus Christ, the sign of this covenant being baptism. God places great honour on the relationship between parents and children and family's being a means of grace, there is a grave responsibility on parents to bring their children up in the Church.
When God entered into his Covenant with Abraham he said: ďAs for you, you shall keep my covenant, you and your offspring after you throughout their generations. This is my covenant, which you shall keep, between me and you and your offspring after you: Every male among you shall be circumcised" (Ge 17:9-10). Circumcision was the sign and the seal of God's covenant with Israel. Galations 5:6 declares that circumcision now counts for nothing and on several occasions the New Testament baptism is contrasted with the now obsolete practice of circumcision. Baptism is said to be the sign and the seal of the new covenant.
Entry into the church is through baptism as a promise of the New Covenant. For this reason parents are to baptise their children who then become members of the Church, whether they are or will become regenerate members of the spiritual Church or merely temporal members of the physical church only time will tell.
The subject of baptism deserves an extended explanation as "believers baptism" is very fashionable in Evangelical circles as such a practice reinforces the genuine importance of the individuals response to the gospel (a good reason) and also resonates with western individualism (a bad reason). The New testament is largely silent on the subject, of course believers are to be baptised as they enter the Church. That is the same then as it is now however the question arises when parents follow Christ and are baptised should their minor children also be baptised? Repeatedly in the New Testament when someone accepted the gospel he was baptised with "his household". Opponents of paedobaptism (the baptism of children) claim that the households did not contain children but this is highly unlikely, Children are spoken to as if they are members of the Church and the promise inherent in baptism are mirrored by the promise inherent in circumcision.
Worship of God is the central activity of the Church and this brings us to one of the great distinctive's of Reformed theology, the much misunderstood Regulative Principles of Worship (RPW). the RPW is very unpopular in this day and age but unless the RPW is accepted there is no church. The RPW at its simplest is that whatever God has not specifically commanded in worship is forbidden. In the Old Testament God repeatedly condemns Israel for not worshiping him in exactly the way that they were instructed and punishments are repeatedly meted out on Israel for its failings in this respect. The human mind is an idol factory and our innovations in worship come from our own sinful minds and fallen natures and will be idolatry. There are internal arguments as to whether the RPW allows the use of music, or whether any but Psalms can be sung in worship but these arguments accept the RPW and are debated within the RPW framework. What is clear is that worship is not down to personal preferences or cultural norms, it has to be in direct accordance with the word of God.What does this mean in practice? Well for a start choir solos are prohibited as are drama and instruction by Women, where the tension is usually felt is over new forms of music that seek to encourage emotion, the gospel is emotive enough when it is understood, if something feels good you have to ask yourself if it is your carnal nature that is being satisfied?