What makes the local visible church distinct, recognizable or different from say a para-church institution? In other words what are the marks of the local church? What is and isn’t a church?

The Belgic Confession says (Article 29) “The true church can be recognized if it has the following marks: The church engages in the pure preaching of the gospel; it makes use of the pure administration of the sacraments as Christ instituted them; it practices church discipline for correcting faults. In short, it governs itself according to the pure Word of God, rejecting all things contrary to it and holding Jesus Christ as the only Head. By these marks one can be assured of recognizing the true church– and no one ought to be separated from it.” download (1)

Theodore Beza says preaching
John Calvin and Heinrich Bullinger say (preaching and sacraments)
Peter Martyr and Zacharias Ursinus say of – preaching, sacraments and discipline.

So the visible manifestation of the universal, holy, one, apostolic church locally can be distinguished by 1)The Word being proclaimed 2) Baptism & Lords Table 3) Discipline. I would consider love to be a mark as well as servant leadership (elders, deacons, etc).

I ask this because it seems many people find it difficult to distinguish a church from other Christian organizations. What say you?