The Church exists primarily to be a corporate worship-of-God event. But, the church also exists for the edification of the saints. God called each believer in the body of Christ to reflect the image of Christ (Rom 8:29) by being holy and blameless before Him (Eph 1:4). Each believer in the church has a responsibility to the church to actively pursue the corporate spiritual growth and maturity of the church.
In order to accomplish this purpose of edifying of the saint, Christ, the head of the church, gave each member in the church a gift of enabling grace (Eph 4:7-10). Furthermore, Christ gave a different particular giftedness to each member in His body to bring about a mutual growth within the church. Church leaders are to exercise their gift in establishing the church on apostolic and prophetic revelation and must lead the church to maturity in doctrine and practice (Eph 4:11-13). But the leaders alone are not responsible for bring the church to spiritual maturity and completeness. Each and every believer in the church has the enabling grace and particular spiritual giftedness that they must exercise to the church for mutual edification (1 Cor 12:7). The fellowship in Christ between the saints is where most of these gifts are exercised. As the church interacts internally each member must seek out the spiritual good of each other member and in service to the other members use his/her gift accordingly.