Is the Church Simply the Set of All the Saved?

One of the major differences Catholics and Protestants have is on the nature of the Church. Is the Church a visible entity founded by Jesus Christ, or simply the invisible collection of all of the saved?  Bible.ca, for example, includes a series of lessons from Ron Boatwright, who argues that “Only The Saved Are In The Lord’s Church”:

Benjamin West, St. Peter Preaching at Pentecost (19th c.)

In order to be in the one church the Lord established, those added to it by the Lord must be saved according to His requirements. In Acts 2:47 we read, “And the Lord added to the church daily those who were being saved.” The Lord only adds the saved to His church. There are no unsaved people in His church. The Lord makes no mistakes. We are not saved just because we think or say we are. We are saved only when we have done what God has said we must do. Jesus says in Matthew 7:21, “Not everyone who says to Me Lord, Lord shall enter into the kingdom of heaven, but he who does the will of My Father which is in heaven.” We must do God’s will, not man’s will, to go to heaven.

But, of course, Acts 2:47 doesn't actually say that only the saved entered the Church.  It says that the saved entered the Church, but doesn't say, “these and only these!”  In context, the passage is talking about the earliest believers, who respond to Peter's message on Pentecost by getting Baptized (Acts 2:41), and are thereby joined to the Church: “Those who accepted his message were baptized, and about three thousand were added to their number that day.”  But the idea that Baptism is the doorway to the Church is the Catholic position.

In any case, nothing in Acts 2 (or elsewhere) proves Boatwright's claims that the “Lord only adds the saved to His church” or that there “are no unsaved people in His church.”  In fact, Jesus explicitly teaches the opposite of this.  In Matthew 13, Jesus lays out a series of parables describing the nature of the Kingdom of Heaven on earth, the Church.  One of the clearest is the parable of the nets, Mt. 13:47-50:

“Once again, the kingdom of heaven is like a net that was let down into the lake and caught all kinds of fish. When it was full, the fishermen pulled it up on the shore. Then they sat down and collected the good fish in baskets, but threw the bad away.  This is how it will be at the end of the age. The angels will come and separate the wicked from the righteous and throw them into the fiery furnace, where there will be weeping and gnashing of teeth.”

Rogier van der Weyden,
Last Judgment (detail) (1452)

That's awfully clear, isn't it? Right now, the Church consists of both the saved and the damned. At the end of time, at the Last Judgment, the damned will be weeded out of the Church, and thrown into Hell.  This is why Boatwright can't use Matthew 7:21 as a proof-text: it's dealing with the Kingdom of Heaven in Heaven, after the Last Judgment.  But Matthew 13 shows that this isn't what the Kingdom of Heaven looks like on Earth, which is the dispute at hand.

Nor is this passage in isolation: shortly before this, Jesus used the parable of the weeds and the wheat, describing the Kingdom as a field with both wheat (the saved) and the weeds, and explaining (Mt. 13:40-41):

“As the weeds are pulled up and burned in the fire, so it will be at the end of the age. The Son of Man will send out his angels, and they will weed out of his kingdom everything that causes sin and all who do evil. They will throw them into the fiery furnace, where there will be weeping and gnashing of teeth.

According to Boatwright, the Kingdom consists of only the saved, and works don't matter at all towards salvation.  Jesus contradicts both of these claims.  He clearly describes the Kingdom as needing to be weeded, and says that this won't happen until the harvest (Mt. 13:30), which represents the end of time (Mt. 13:39).  And some members of the Kingdom are thrown into the fiery furnace at the end of time.  That doesn't sound like salvation to me.

So I agree with Boatwright when he says that “The Lord makes no mistakes.”  But the same cannot be said for those claiming the Church consists solely of the saved.  What Scripture clearly describes in Matthew 13 and numerous other places is a visible Church consisting of both the saved and the damned, and entered into through Baptism.