I've thought about this overnight. Are you implying souls added to the church were not saved?
Paul uses the same Greek word here:
1 Cor. 15:2 and by which you are being saved, if you hold fast to the word I preached to you—unless you believed in vain. ESV
Acts 2:47 praising God and having favor with all the people. And the Lord added to their number day by day those who were being saved.ESV
He and some of his pals on here do not hold the assembly at Jerusalem was saved but have to wait for their salvation when the Lord returns.
They hybrid or confuse Israel's yet future National salvation, with each Israelite's personal, individual salvation.
So he reads said bias into passages like that one.
But the thing is referring to the present result of a past action.
Fact is, the word "should" has different uses, and one of them is the issue of a present result being the result of a past action on someone's part.
Further, the fact of the matter is that that phrase is in the KJV an earlier form of asserting that:
Praising God, and having favour with all the people. And the Lord added to the church daily such as should be saved.
What it it is relating is the continuing daily growth of their assembly due to the Lord's adding to it those who were being saved, in other words; those who were believing.
It is saying He was adding new saved people to their assembly, daily.
But it is saying that in an Earlier form of Modern English, and that; a translation of how the thing was expressed even further back to some 1,500 years earlier.
Even in the more modern "translations" the sense will tend to end up a bit complicated - because the translation is still a translation of a way of saying a thing some 2,000 years ago.
Thus, the "were being saved" relates, or points back to the idea that more and more converts were being "added to their number day by day."
In other words, people were being saved - new converts were being added - to their growing number...daily.
Which is what Rules of Grammar are for: for following said rules towards getting at the proper sense.
As James would later note...
Acts 21:20 And when they heard it, they glorified the Lord, and said unto him, Thou seest, brother, how many thousands of Jews there are which believe; and they are all zealous of the law:
And then you have to other kind of incompetent. The person who claims the Spirit gives them their understanding of the passages.
Never mind the many who claim that who each nevertheless end up at anything but on the same page with one another.
As if the Spirit Himself did not follow the rules of grammar He expected those He gave His Words to write down to follow.
Joshua 24:26 And Joshua wrote these words in the book of the law of God, and took a great stone, and set it up there under an oak, that was by the sanctuary of the LORD.
Nehemiah 8:8 So they read in the book in the law of God distinctly, and gave the sense, and caused them to understand the reading.
8:12 And all the people went their way to eat, and to drink, and to send portions, and to make great mirth, because they had understood the words that were declared unto them.
Nope, some of the called "MADs" on here continue to prove highly suspect in their actual understanding of the most basic of role of the rules of grammar in both the ccommunication, and the inderstanding of intended sense, through said rules.
Even as they ridicule others about their grammar and or understanding...
Rom. 5:8.
