1 Cor 6: once you were such—but you were washed, sanctified, justified
Paul contrasts their justified state with their former vices (1 Cor 6).
That contrast collapses if they were already justified while still immersed in sin.
Latin
XV. Praeterea eodem in loco, Apostolus satis evidenter opponit praesentem fidelium statum, in quo a peccatis justificati erant, conditioni eorum praecedenti in qua flagitiis variis indulserant. Quae oppositio vana & nulla esset, si, etiam antequam illis renunciarent, & quum illis adhuc immersi jacerent, jam tum nihilominus erant justificati. Et haec quidem, inquit, eratis, nempe scortatores, idololatrae, moechi, masculorum concubitores, fures, avari, ebriosi, maledici, rapaces; sed abluti estis, sed sanctificati estis, sed justificati estis, in nomine Domini Jesu, & per Spiritum Dei nostri.