In Christianity there are many views about a topic and this my view. The Church is an outpost of the Kingdom of Heaven in a world ruled by the ‘Prince of the Power of the Air’.
Miriam-Webster Dictionary cites this as one definition of outpost: an outlying branch or position of a main organization or group.
The main group would be the Kingdom based in heaven or the heavenly Mt. ZIon. From there came the Son of God to initiate the presence of the Kingdom of Heaven on the earth. As He ascended back to heaven ten days later would come Pentecost, the outpouring of the Holy Spirit which inaugurated to New Covenant and the beginning of the Church as we know it.
Thus a Church is an outpost of the Kingdom of Heaven. As such the Church signifies to the seen and unseen world that the God of all creation has established His presence in an area and from that location evangelists are sent out to call sinners to repentance and faith in the Son of God the Lord Jesus Christ.
As sinners believe they enter the Church and begin the process of discipleship. As the Church grows it should seek to establish another outpost for the exact same purpose: to call sinners in that area to repentance and faith in the Lord Jesus Christ and for those who do believe they will enter the discipleship process.
An on and on the process goes as more outposts of the Kingdom are established, more evangelists sent out, more sinners hear the Gospel, believe and are discipled. Thus the evangelist’s key role is the going into the highways and hedges to call sinners to repentance and faith.
Views from an Evangelist 