The Greek text of the Textus Receptus (1550) states,
ΚΒʹ δικαιοσύνη δὲ θεοῦ διὰ πίστεως Ἰησοῦ Χριστοῦ εἰς πάντας καὶ ἐπὶ πάντας τοὺς πιστεύοντας οὐ γάρ ἐστιν διαστολή TR, 1550
which Jerome translated into Latin as,
XXII iustitia autem Dei per fidem Iesu Christi super omnes qui credunt non enim est distinctio Vul
In English, it would be acceptable to translate διὰ πίστεως as “by [the] faith of” and τοὺς πιστεύοντας as “those who have faith,” thus emphasizing the similarity in the Greek stem πιστ-.
I noticed that Jerome translated πίστεως into Latin as fidem, from the lemma fidēs, but using a different root altogether, he translated τοὺς πιστεύοντας into Latin as qui credunt.
Rather than crēdunt from the lemma crēdō, why didn’t Jerome instead use fīdunt from the lemma fīdo?