Greek: singular: ἀδελφός (adelphos)
plural: ἀδελφοί (adelphoi)
English: singular: brother; a person
plural: brothers; brothers and sisters
by Mark D. Taylor, NLT Bible Translation Committee
The Greek word adelphos (pronounced ah-del-FOS) appears 343 times in the New Testament—often in the plural adelphoi (pronounced ah-del-FOI). Its most common translation into English is “brother” or “brothers,” as in Matthew 4:18:
One day as Jesus was walking along the shore of the Sea of Galilee, he saw two brothers—Simon, also called Peter, and his brother Andrew.
Simon Peter and Andrew were indeed siblings. In the Gospels, this is the most common meaning of adelphos. It refers to a male sibling.
But sometimes adelphos refers generically to an unspecified person. For example, in Matthew 5:23-24 we read:
So if you are presenting a sacrifice at the altar in the Temple and you suddenly remember that someone has something against you, leave your sacrifice there at the altar. Go and be reconciled to that person. Then come and offer your sacrifice to God.
The context suggests that this principle is to be applied in one’s relationship with anyone, not simply a male sibling.
The term is also used in a metaphorical sense to refer to other believers. Those in the early churches began to view one another in a warm, familial sense akin to how they would view a sibling. This usage is especially prevalent in Acts and the Epistles. For instance, in Romans 1:13 we read:
I want you to know, dear brothers and sisters,* that I planned many times to visit you, but I was prevented until now. I want to work among you and see spiritual fruit, just as I have seen among other Gentiles.
1:13 Greek brothers.
The Greek text here in Romans (and also in other NT letters) uses adelphoi, a grammatically masculine noun. But note that the NLT renders it as “brothers and sisters,” as it does frequently throughout Acts and the NT letters. Many of the messages in Paul’s letters include greetings to particular women, making it clear that he was writing to both men and women in the church. Thus, we can rightly understand that Paul frequently had both male and female believers in mind when he used this umbrella term.
Many modern translations recognize this meaning through the use of a footnote. When the NLT renders adelphoi as “brothers and sisters,” it includes a footnote that reads “Greek brothers.” The NIV also renders it as “brothers and sisters” (with a similar footnote). The ESV renders it as “brothers,” with a footnote that reads “Or brothers and sisters. In New Testament usage, depending on the context, the plural Greek word adelphoi (translated “brothers”) may refer either to brothers or to brothers and sisters.”
In some instances, the text uses adelphoi in a context that clearly refers specifically to the male believers. For example, in Acts 1:14-16 we read,
14 They all met together and were constantly united in prayer, along with Mary the mother of Jesus, several other women, and the brothers of Jesus.
15 During this time, when about 120 believers were together in one place, Peter stood up and addressed them. 16 “Brothers,” he said, “the Scriptures had to be fulfilled concerning Judas, who guided those who arrested Jesus. This was predicted long ago by the Holy Spirit, speaking through King David.
The highlighted term in verse 15 reflects the metaphorical use of adelphoi (see the mention of women in verse 14), so the NLT renders it as “believers.” But in verse 16 the Greek text uses two words that can be literally translated as “Men, brothers.” So it is clear that Peter was speaking specifically to the men in the crowd. Accordingly, the NLT renders it as “Brothers” rather than “Brothers and sisters.”
Today, you might hear a pastor refer to the believers in the congregation as “brothers and sisters,” and such family-type language is appropriate in light of New Testament usage. May we indeed consider fellow believers as near and dear to us, treating them with love and care—just as we should treat our actual siblings.