The Gates Of Hell Shall Not Prevail : What Does It Mean ?

[MagisterMusicae]

Does it mean it has to be visible?

The visibility of the Church is a necessary quality due to its very constitution as a perfect society.

A society is a quasi-permanent institution made up of individuals who are united in common means towards a common end by an authority. The Church is just such a society. By "perfect" we mean it contains within itself all of the means necessary to reach its goal.

Now, the authority is the very principle of unity and organization, it is necessary for there to be a society. While an absence of the actual authority for a short time might be possible, a permanent absence would mean the absence of the principle of organization and movement, and thus the destruction of the society.

It is not some loose moral union (which is the Protestant notion of the Church), but a union which exists as caused by this authority. That authority makes the society "visible" and thus identifiable.

So while it is certainly possible for the visibility of the Church to be somewhat eclipsed, it is impossible that it be an entirely invisible union (a moral union). There must always be an actual union, which requires an actual authority.

Thus the Church must be visible, if it be Christ's Church.

[Eric F]

The Church was probably close to being invisible over the first 3 centuries of it's existence.

[MagisterMusicae]

The Church was probably close to being invisible over the first 3 centuries of it's existence.

There was always a hierarchy and Pope, so always that principle of unity, and thus a society.

Perhaps you have an incorrect view of the first three centuries of the Church's existence. The first Empire-wide persecution is not until 250. Plenty of local persecutions happened, but the Church was known and quite visible. Various emperors even approved and tolerated the Church before 313, such as under Gallienus. It was recognized as a burial society by the Empire, which is why Constantine was able to "restore" to it various properties that were taken.

Seems pretty visible to me.