ISB ~ Philippians 4 v3

co-worker:The Greek, here rendered as a descriptive title, can also be translated as a personal name, “Syzygus”. Whatever the case, Paul is asking a particular individual to facilitate a peaceful resolution to the conflict between Euodia and Syntyche (4:2).

Clement:Otherwise unmentioned in the NT. Early Christian tradition identifies him as Clement of Rome, the fourth bishop of Rome (after Peter, Linus, and Anacletus) and the author of an ancient epistle known as 1 Clement (Eusebius, Ecclesiastical History 3, 15-16; St. Jerome, On Illustrious Men 15).

the book of life:A registry of the saints kept in heaven (Dan 12:1; Lk 10:20). God alone knows the complete list of names since he alone made the entries (Ex 32:32).