What is the role of the church for the believer and the family? What does the Bible teach about the role of the church
The word church is from the Greek word “ekklesia” which means “an assembly” or literally the “called-out ones/assembly,” so the church are those whom God has called and saved through repentance and faith in Christ. The word church is hardly mentioned at all until after the gospels, but then it is frequently called by name (Rom 16:5; Gal 1:1-2). Strictly speaking, the church is the Body of Christ, doing the work that the Head of the Church directs (i.e. Matt 25:25-26). Jesus directs the Bride of Christ, the Church, to be glorifying God and seeking the lost. By being called the Body of Christ, the church is to be the hands, mouth, eyes, and feet of Christ on earth. Each member has been gifted by God to perform a vital function in the church so that the church is edified, encouraged, and grows in the grace and knowledge through the expository preaching of the Word of God. Each member works in unison with other members and for one another, with each member having a unique function, enabling the Body of Christ to perform what she was created to do. 
The Church’s Purpose
The church has been given the responsibility of instructing the members to grow in both the grace and the knowledge of God, commanding them to “grow up in every way into him who is the head, into Christ, from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love” (Eph 4:15-16). This is “so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes” (Eph 4:14). This equipping come from the Word of God and is designed “to equip the saints for the work of ministry, for building up the body of Christ, until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ” (Eph 4:12). God has assigned each member as it pleases Him, so it was He that “gave the apostles, the prophets, the evangelists, the shepherds and teachers” the responsibility to oversee these functions (Eph 4:11). What part do you take in the Body?
A Healthy Church
A healthy church is one where its members are disciplined whenever necessary; that the sacraments are biblically administered on a regular basis, and that the Word of God is preached, hopefully verse by verse, so that the flock can grow and mature, moving toward the stature or nature of Christ. The early church grew rapidly because “they devoted themselves to the apostle’s teaching and the fellowship, to the breaking of bread and the prayers” (Acts 2:42). They were all unified in mind and purpose so that “all who believed were together and had all things in common” (Acts 2:44). When they continued “praising God and having favor with all the people…the Lord added to their number day by day those who were being saved” (Acts 2:47). That’s the real way to grow a church. Have church discipline (Matt 18:15-20), administer the sacraments, and preach the Word…in and out of season. We read about three things mentioned in the early church that caused growth: They devoted themselves to the apostle’s teachings, which they had received from Christ; they had fellowship and the breaking of bread, which were meeting often and eating together; and they prayed. If any one of these three is missing, then the church will not function in the way that it was designed to function. These three essentials resulted in God growing the church.
Seeks the Lost
A church that grows is also one that goes…, meaning they seek those who are lost. They don’t ignore the imperative command given by Christ just before His ascension (Matt 28:18-10; Acts 1:8) to go into all the world. Jesus’ mission on earth was to rescue the perishing (Mark 10:45), and the church must have that same purpose if she is to grow. God will not bless any church that does not care about the lost. Our Lord Jesus Christ certainly did. The word Christian means to be “Christ-like” or “little-Christ’s,” and to be following in the footsteps that He took while on earth, and clearly He was sent “to seek that which was lost” (Luke 19:10). Are we seeking the same thing?
The Role of the Church
The biblical definition of the church has been mentioned briefly in the previous paragraphs. She is to grow her members, feed them the Word of God, to fellowship together, to administer church discipline when needed, have communion regularly, to grow in grace and knowledge, to go into all the world with the gospel, making disciples of others, teaching them the same thing Jesus taught His disciples (found in the gospels), regularly praying for one another, and loving one another as Jesus loved us (John 13:35-35). Pastors, elders, deacons, teachers, and other leaders have been placed in the Body as it pleases God, and they’re responsible for ensuring that the members are well enough versed in Scripture to discern error, to know how to proclaim the gospel to the lost and to discipline members where and when needed.
Church discipline is vital to the church remaining as holy as possible and for the betterment not only of the Body of Christ (Matt 18:15-20), but it’s also in the best interests of the unrepentant and openly sinning members. Paul said as much when he wrote “Now we command you, brothers, in the name of our Lord Jesus Christ, that you keep away from any brother who is walking in idleness and not in accord with the tradition that you received from us” (2 Thess 3:6). This was a command, not a suggestion. For example, there was a man who was having sexual relations with his father’s wife (1 Cor 5:1), so Paul told the church at Corinth what to do; “Let him who has done this be removed from among you” (1 Cor 5:2b), and “Purge the evil person from among you” (1 Cor 5:13b). Paul commanded this in the best interests of the church, but also for this sinning man’s soul. Paul commanded them that “you are to deliver this man to Satan for the destruction of the flesh, so that his spirit may be saved in the day of the Lord” (1 Cor 5:5). So if there is a church member that is openly sinning and refuses to repent, then that member is to be disfellowshipped in the hopes that they would repent and confess their sin and turn again to obedience. It is at that point that the church is to accept him or her back into the fold, and to do so lovingly (1 Cor 5). 
Loving the Members
Some say that they don’t get much out of church, but is that what they’re really there for…to get something for themselves? Church is about giving and serving and coming to God to give Him proper worship in spirit and in truth. God seeks these kinds of worshippers (John 4:23). It’s not about what you can get out of church but about what you can do in the service of God. Some say that they love the Father but they can’t stand His children. They love Christ but they don’t love the members of His Body. Do you see the contradiction in that? If one of my children came up to me and said they love me, their father, but they can’t stand to be around my other children. Clearly, I would not be pleased at that.
When we all stand before the judgment seat of Christ someday and some may say, “Well, I love you but I didn’t like the way the rest of your body members acted so I stayed away from the church.” They justified their willfully breaking the command to assemble together (Heb 10:24-25). There is no “lone ranger” or church-less Christian in the New Testament church. The Christian life was never meant to be a solo act. That makes them more vulnerable to the Devil and his demons. The members of Christ’s body need one another. His body does not have individual body parts scattered everywhere. They are assembled together as one body to function as only a body can…with all the necessary members working together. We need to be praying for one another, loving one another, serving one another, and be worshipping together. Jesus said I will build My church and the gates of hell or death would not prevail against it. So what makes us think that we don’t need it?
Here is some related reading for you: What Does the Bible Say About Church Membership and Attendance? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.