Faith And Sin

Omne enim quod non est ex fide peccatum est... Non enim omnis actus tantum, sed omnis infidelium vita peccatum est. Ubi enim deest agnitio incommutabilis veritatis, falsa virtus est, etiam in optimis moribus. Nam, sicut jam dictur est, et saepe dicendum est et firmiter credendum est, optima opera fiunt ab homine, fides autem fit in homine, sine qua nulla bona opera fiunt ab ullo homine, quia peccatum est quidquid ex fide non est. Peccat ergo, qui non cum fide manducat, semetipsum vero ille judicat, cujus exemplo infirmus peccat. In suo enim genere curandum est quod ad melius interum perduci non potest. Guillelmus S Theodorici Abbas, Expositio In Epistolam Ad Romanos, Lib VII, Caput XIV Source: Migne PG 180.686a

Everything that is not from faith is sin. 1 And not even every act but the whole life of the faithless is sin. Where there is the lack of the immutable truth, virtue is false, even in the best conduct. For as has been said, and as must often be said and firmly believed, the best works come from a man, but faith is made in a man, without which no good works come from any man, because whatever is not from faith is sin. Therefore he sins who does not eat with faith, however he judges himself, by whose example the weak man sins. For his care must be for his own kind which meanwhile cannot lead to what is better. William of St Thierry, Commentary on Romans, Book 7, Chapter 14 1 Rom 14.10