How big was the community of believers in Jesus during the early years of the Christian movement? What can we learn from the Bible about the size of the community of believers in Jerusalem? Was it just an insignificant number or was a large portion of the population of Jerusalem part of this movement?
This is an interesting question because it helps us compare the early Jewish-Christian church and the other part of the Judean population that did not accept Jesus. For much of Christian history the Jewish people have been portrayed as those who rejected Jesus, yet Jesus and all of his followers were Jewish. If through study we determine that the early Jewish-Christian church was a substantial portion of the Judean population then it changes our picture of them. If it is a big church— a substantial percentage of the total population— then it is a social (and political) force in Judea rather than a persecuted minority.
Perhaps it would be helpful to start with some texts from the time of Jesus' ministry. There are quite a few that talk about the size of the crowds that gathered around him.
Matt 4:25 NKJV Great multitudes followed Him—from Galilee, and from Decapolis, Jerusalem, Judea, and beyond the Jordan.
There are many texts that talk about the “multitudes” that followed Jesus. Following is a NKJV concordance of the Gospel texts that use these words. (Some of these texts may be about something other than the crowd following Jesus.)
multitude: Matt 13:2, 34, 36; 14:5, 14; 15:10, 31–33, 35–36, 39; 17:14; 20:29, 31; 21:8, 26; 26:47; 27:15, 24; Mark 2:13; 3:7–9, 20, 32; 4:1, 36; 5:21, 24, 31; 6:34, 45; 7:14, 33; 8:1–2, 6; 9:14; 10:46; 12:12; 14:43; 15:8; Luke 1:10; 2:13; 5:1; 6:17, 19; 8:4, 37, 40; 9:12, 16, 37–38; 12:1; 13:17; 18:36; 19:37; 22:6, 47; 23:1, 27; John 5:3, 13; 6:2, 5; 12:12; 21:6
multitudes: Matt 4:25–5:1; 8:1, 18; 9:8, 33, 36; 11:7; 12:15, 23, 46; 13:2; 14:13, 15, 19, 22–23; 15:30; 19:2; 21:9, 11, 46; 22:33; 23:1; 26:55; 27:20; Mark 6:33; 10:1; Luke 3:7; 5:3, 15; 7:24; 8:42, 45; 9:11; 11:14; 12:54; 14:25
There are also many texts that mention that "many" of the people believed. John 11:48 and John 12:42 are especially helpful. The chief rulers considered Jesus the head of a popular movement that threatened their hold on power; a handful of followers would not have been a threat to them.
Mark 11:18 NKJV And the scribes and chief priests heard it and sought how they might destroy Him; for they feared Him, because all the people were astonished at His teaching.
Luke 1:16 NKJV And he will turn many of the children of Israel to the Lord their God.
John 2:23 NKJV Now when He was in Jerusalem at the Passover, during the feast, many believed in His name when they saw the signs which He did.
John 4:39 NKJV And many of the Samaritans of that city believed in Him because of the word of the woman who testified, “He told me all that I ever did.”... 41 And many more believed because of His own word.
John 7:31 NKJV And many of the people believed in Him, and said, “When the Christ comes, will He do more signs than these which this Man has done?”
John 7:40 NKJV Therefore many from the crowd, when they heard this saying, said, “Truly this is the Prophet.”
John 8:30 NKJV As He spoke these words, many believed in Him.
John 10:41 NKJV Then many came to Him and said, “John performed no sign, but all the things that John spoke about this Man were true.” 42 And many believed in Him there.
John 11:45 NKJV Then many of the Jews who had come to Mary, and had seen the things Jesus did, believed in Him.
John 11:48 NKJV If we let Him alone like this, everyone will believe in Him, and the Romans will come and take away both our place and nation.”
John 12:10 NKJV But the chief priests plotted to put Lazarus to death also, 11 because on account of him many of the Jews went away and believed in Jesus.
John 12:42 NKJV Nevertheless even among the rulers many believed in Him, but because of the Pharisees they did not confess Him, lest they should be put out of the synagogue;...
There are several texts that give specific numbers about the size of the crowd following Jesus.
Matt 14:21 NKJV Now those who had eaten were about five thousand men, besides women and children.
Matt 15:38 NKJV Now those who ate were four thousand men, besides women and children.
Here is a NKJV concordance of Gospel texts that use the word "thousand" to talk about the size of the crowd:
Matt 14:21; 15:38; 16:9–10; Mark 6:44; 8:9, 19–20; Luke 9:14; John 6:10
The words of Cleopas on the walk to emmaus gives us a clue about the scale of the popular movement around Jesus. He expected that everyone in Jerusalem would know about it.
Luke 24:18 Then the one whose name was Cleopas answered and said to Him, “Are You the only stranger in Jerusalem, and have You not known the things which happened there in these days?”
Early in the book of Acts we are already seeing that there were a group of 5,000 believers; and 3,000 were being added in one day. Even among the priests (see also John 12:42), there were many believers.
Acts 2:41 NKJV Then those who gladly received his word were baptized; and that day about three thousand souls were added to them.
Acts 4:4 NKJV However, many of those who heard the word believed; and the number of the men came to be about five thousand.
Acts 5:14 NKJV And believers were increasingly added to the Lord, multitudes of both men and women,... 16 Also a multitude gathered from the surrounding cities to Jerusalem, bringing sick people and those who were tormented by unclean spirits, and they were all healed.
Acts 6:7 NKJV Then the word of God spread, and the number of the disciples multiplied greatly in Jerusalem, and a great many of the priests were obedient to the faith.
By Acts chapter 6, what is the likely size of the church? If it was more than 5,000 earlier and now it has “multiplied greatly” then it must be at least three or four times what it was before— perhaps 20,000 or more. Judea is not a big place, so that is a substantial number.
The last text in Acts that gives us information about the size of the early Christian community in Jerusalem is Acts 21:20. Unfortunately, this text is translated inconsistently and probably inaccurately in many English translations.
Acts 21:17 NKJV And when we had come to Jerusalem, the brethren received us gladly. 18 On the following day Paul went in with us to James, and all the elders were present. 19 When he had greeted them, he told in detail those things which God had done among the Gentiles through his ministry. 20 And when they heard it, they glorified the Lord. And they said to him, “You see, brother, how many myriads of Jews there are who have believed, and they are all zealous for the law;....
The NKJV isn't inaccurate, but the word myriads is simply a transliteration of the Greek word. The English word myriads means:
1 a countless or extremely great number
2 (chiefly in classical history) a unit of ten thousand
The primary meaning of the Greek word myrias used in this text is 10,000. Some readers may not be aware of the "classical" meaning of myriad as 10,000 and many other English versions simply translate this this word as thousands.
NASB — how many thousands there are among the Jews of those who have believed
KJV — how many thousands of Jews there are which believe
NIV — how many thousands of Jews have believed
What is the smallest number that a reader might think "many thousands" to mean? It is certainly more than 2,000 and very unlikely to be less than 4,000 to 5,000. Given the texts from earlier in the chapter, the reader might think that this means 10,000 or maybe 20,000. If we say "many tens of thousands", that creates quite a different picture. That probably means at least 50,000 and maybe 100,000 or more. Why do so many translations translate this text using thousands rather than tens of thousands. Is there a translation bias? Did the translators disbelieve the literal words of the text? Here are a few examples of translations that give the reader a clearer picture of the underlying Greek text.
CJB — On hearing it, they praised God; but they also said to him, “You see, brother, how many tens of thousands of believers there are among the Judeans, and they are all zealots for the Torah.
CEV — Everyone who heard this praised God and said to Paul: My friend, you can see how many tens of thousands of the Jewish people have become followers! And all of them are eager to obey the Law of Moses.
ISV — When they heard about it, they praised God and told him, “You see, brother, how many tens of thousands of believers there are among the Jews, and all of them are zealous for the Law.
LEB — And when they heard this, they began to glorify God. And they said to him, “You see, brother, how many ten thousands there are among the Jews who have believed, and they are all zealous adherents of the law.
How does this change our picture of the early church? Many tens-of-thousands of Torah-observant Jewish believers in Jesus the Messiah— perhaps more than 100,000— are a large part of the population of Judea. It actually helps us understand the rapid growth of the church in the rest of the Roman Empire— and also in the East. It is made possible by a Jewish population, both in Jerusalem and the Diaspora, where a significant number readily accept Jesus. We should not say that the Jews rejected Jesus— because a large number did accept Jesus.