The true church is the body of believers who are citizens of The Kingdom of God. The denomination is a manmade organization for the purposes of beliefs or practices that is not in the traditional true Church which they believe should be part of the true church. So, while they may have the correct doctrine, they believe the true church is not doing the correct thing in an area. This leads to prejudice and a lack of love or disunity as they promote what they do as correct and look down on churches that do not have them in their beliefs. And so, the next denomination believes the original one is not doing what it should in an area and the cycle continues.
This leads to the absurdity that the last denomination formed is believed by its members to be the true Christian church even though it is far removed at times in doctrine and/or practice from what Jesus taught the early church.
The church is the representative of God on Earth and everything it does is towards this purpose of telling other what God desires them to know, helping them understand it and live the life they need too. The denomination may use worldly things to do this but they are only vehicles and not end in themselves.
The true church does not promote the denomination, people or activities but Jesus and His teaching.
It demonstrates what it means to be a Citizen of The Kingdom of God and show God’s quality of love in all it does.
If Jesus and his purposes are not Central to all they do then the church is not a Christian church but a look alike the give the impression of one but does not do the work of one
The purpose of the true Christian church is to:
Evangelise – proclaim who Jesus is and what He has done for them
Nurturing people in their Christian life
Training them to do the work of Jesus
Demonstrating that Jesus and The Kingdom of God are real by their authority over Satan and Nature.
Living the Christian life to show it is worthwhile living.
Any church not doing these things is not a Christian church as it is not following Jesus as it should unless it does not know how to because the members have not been taught these things.
Having said that, God judges you on what you do with what you know and not on what you are supposed to know as He looks at the heart attitude towards Him and not its results.