Growing up with the KJV, I learned Acts 2:47 as
And the Lord added to the church daily such as should be saved.
Later in life, I moved to the NIV, which reads,
And the Lord added to their number daily those who were being saved.
Where did the church go? One explanation is that the evil NIV hated the church and thus remove mention of it from this text. However, that explanation would be wrong.
The answer to which translation is correct comes down to the matter of how the manuscripts of the NT were preserved and eventually came down to us.
Actually the NT manuscripts (MSS) contain some variations. The “best” reading is ἐπὶ τὸ αὐτό (to thier group/number) instead of τῇ ἐκκλησία (to the church). That is, some MSS of the NT have the first reading while the majority of MSS have a variation of the latter.
The first reading (ἐπὶ τὸ αὐτό) is supported by 01 02 03 04 81 1175.
However regarding the addition of “church,” the following readings are attested in the MSS:
τη εκκλησια 08 014sup1 025 044 049 056 1 33 69 88 226 323 330 440 547 614 618 927 1241 1245 1270 1505 1611 1646 1828 1837 1854 2147 2344 2412 2492
τη εκκλησια επι το αυτο 35 945 1739 1891
εν τη εκκλησια 104 1243
+ εν τη εκκλησια 05
της εκκλησιας επι το αυτο 2495
Metzger, in his Textual Commentary, offer the following explanation for the rise of the jumbled secondary readings:
The phrase ἐπὶ τὸ αὐτό, which is common enough in classical Greek and in the Septuagint, acquired a quasi–technical meaning in the early church. This meaning, which is required in 1.15; 2.1, 47; 1Cor 11.20; 14.23, signifies the union of the Christian body, and perhaps could be rendered “in church fellowship.”91 Not perceiving this special usage of the word in ver. 47, scribes attempted to rearrange the text, either by moving the phrase to the following sentence (3.1) or by glossing it with an equivalent phrase, ἐν τῇ ἐκκλησίᾳ.
This being the case, therefore, the first time Luke uses the word “church” (εκκλησια) is Acts 5:11 (followed by Acts 7:38; 8:1, 3; 9:31; 11:22, 26; 12:1, 5; 13:1; 14:23, 27; 15:3-4, 22, 41; 16:5; 18:22; 19:32, 39-40; 20:17, 28).
While I’m certain the Lord adds people to the church, I’m also certain Luke did not use the word church here–now those later scribes . . . well, that’s a different matter and another topic.