Judgement And Salvation

Οὔτε ἡ ἀρετὴ, οὔτε ἡ κακία μένει αμετάπτωτος, καὶ ἀκίνητος, ἐπειδὴ ἐθελότρεπτόν ἐστι ἀνθρώπινον γένος. Ὂνπερ τοίνυν ὑπολαμβάνεις τὸν ἀδελφὸν ἀμελέστατον εἶναι, ὅνπερ νομίζεις ἁμαρτωλὸν ὑπο ἄρχειν, οὐκ οἶδας, μήποτε καθ' ἑαυτὸν στενάξας, καὶ μεταβαλλόμενος ἐπὶ τὸ κρεῖττον, παρὰ Θεῷ σώζεται. Σὺ δὲ ἀγονῶν εὐτελίζεις πολλάκις τὸν τοιοῦτον, καὶ λοιδορεῖς , καὶ πικρῶς κατακρίνεις τὸν ὑπὲρ σὲ σωζόμενον ἄνθρωπον. Ἅγιος Νειλος, Βιβλιον Δεύτερον, ΡΚΔ' Εὑλυσιῳ Μοναχῳ Source: Migne PG 79.253b

Since the human race is changeable neither virtue nor wickedness remain constant and unchanging. He, then, whom you reckon to be the most negligent brother and whom you judge to be a sinner, you do not know that  sometimes he groans over himself and is changing into something better, being saved by God. And being ignorant you often think such a man is worthless and you abuse and bitterly scorn him who is being saved over you. Saint Nilus of Sinai, Book 2, Letter 124 to Eulysios the Monk