The reciprocal pronoun meaning 'one another' or 'each other.' It appears in over 100 NT verses, forming the backbone of Christian community ethics — the 'one another' commands that define life together in the body of Christ.
The allēlōn commands are the DNA of Christian community: love one another, forgive one another, bear one another's burdens, encourage one another, serve one another. These are not optional extras but the essential marks of the church. The frequency of allēlōn in the epistles shows that Christianity was never meant to be individualistic — it is inherently communal, relational, and mutually dependent.