Acts 15:1

Then some men came down from Judea and were teaching the brothers, “Unless you are circumcised according to the custom of Moses, you cannot be saved.”
BSB · Berean Standard Bible
And certain men which came down from Judæa taught the brethren, and said, Except ye be circumcised after the manner of Moses, ye cannot be saved.
KJV · King James Version
Some men came down from Judea and taught the brothers, “Unless you are circumcised after the custom of Moses, you can’t be saved.”

Note The word for “brothers” here and where the context allows may also be correctly translated “brothers and sisters” or “siblings.”

WEB · World English Bible
And certain men came down from Judæa and taught the brethren, saying, Except ye be circumcised after the custom of Moses, ye cannot be saved.
ASV · American Standard Version

Related passages

From the Treasury of Scripture Knowledge, grouped by the word they explain.

certain
Acts 21:20; Galatians 2:4, 12, 13
the brethren
Acts 15:23
Except
Acts 15:5; Romans 4:8–12; Galatians 5:1–4; Philippians 3:2, 3; Colossians 2:8, 11, 12, 16
after
Genesis 17:10–27; Leviticus 12:3; John 7:22
ye
Acts 15:24; 1 Corinthians 7:18, 19; Galatians 2:1, 3; Galatians 5:6; Galatians 6:13–16