The short answer is that the Bible gives sufficient information about the really important qualities of the church to allow one to recognize whether one is dealing with a church as described in the New Testament, or an institution which is more or less of human design. At least five important characteristics of New Testament churches are easily identified in Scripture. They are:
1. The nature of the church
2. The relationship of local churches
3. The divine plan for leadership
4. Roles and relationships among the people
5. The mission of the church
The fact that it is revealed that there is intense spiritual warfare waged against whatever God is building, accounts for the fact that there are many counterfeits in the world purporting to be the true church.
If you’re looking for a short article on the subject, please begin here.
For a more extended discussion, including the five characteristics of New Testament churches, please see here.