Your notion of church is the institutional church which will always attempt to define those that are “in” and those that are “out”. St. Thomas Aquinas said: The church is precisely the state of communion of the whole world" and “The body of the church is constituted by the people who existed from the beginning of the world until now.” -
This communion does not exist when religious people use doctrine and dogma to exclude. It exists only and precisely when that same doctrine and dogma is used to include all people at all times.
Wherever there is faith, hope, and charity, there is church and there is God.
This warm, fuzzy definition of “church” is appealing to those who essentially want to go their own way, but it is not terribly useful for those who are earnestly seeking to follow God as closely as possible.
Fortunately, there is so much more than a loose association of believers.
Christ promised the gates of hell would never prevail against his Church (meaning that it would always exist). Several factors in the text show he was talking about a visible communion.
First, Jesus made Peter head of this Church (Matt. 16:18), yet Jesus was certainly not making Peter the head of an invisible Church. It is Christ’s own prerogative to be head of the invisible communion of Christians stretching from heaven to earth (Eph. 5:23). Therefore, he must have made Peter the head of a visible, earthly church. (We will not argue here that Jesus made Peter the head; even if one disagrees, the remaining arguments prove our case.)
Second, Jesus gave Peter the keys to the kingdom of heaven (Matt. 16:19), which are for use in Church government (compare Isa. 22:22 – the only Old Testament parallel to this verse). But one cannot govern an invisible communion of believers, only a visible one.
Third, Jesus gave Peter the power of binding and loosing (Matt. 16:19), which Matthew 18:17-18 indicates is used in Church discipline. But one cannot exercise Church discipline over an invisible body. Indeed, Matt. 18:17-18 refers it to public excommunication, in which an individual is treated by the church as “a gentile or a tax collector” (that is, as an unbeliever).
Fourth, Jesus explicitly stated that Peter would exercise the power of binding and loosing on earth. This shows his authority is an earthly one, over an earthly Church.
Fifth, Jesus promised the gates of hell would not prevail against his Church (Matt. 16:18), meaning that it would never perish. But it would be ridiculous to promise that an invisible Church would not pass out of existence since some of the Church’s members are in heaven and Christ’s heavenly Church cannot pass away by its very nature. Only a visible, earthly communion needs a promise that it will never perish.
There are thus abundant reasons to conclude that the Church Jesus was discussing in Matthew 16:17-19 was a visible communion of believers, and, since only the Catholic Church goes back that far, only it can be the one Christ founded.
Hope this helps. :tiphat: