John Chrysostom

Wherefore "exhort ye one another daily, while it is called to-day." That is, edify one another, raise yourselves up: lest the same things should befall you. "Lest any one of you be hardened by the deceitfulness of sin." Seest thou that sin produces unbelief? For as unbelief brings forth an evil life, so also a soul, "when it is come into a depth of evils, becometh contemptuous", and having become contemptuous it endures not even to believe, in order thereby to free itself from fear. For "they said", "The Lord shall not see, neither shall the God of Jacob regard." And again, "Our lips are our own: who is Lord over us?"; and again "Wherefore hath the wicked man provoked God to wrath?"; and again, "The fool hath said in his heart, there is no God; they are corrupt and become abominable in their doings." "There is no fear of God before his eyes, for he was deceitful before Him, to find out his iniquity and to hate." Yea and Christ also says this same thing, "Every one that doeth evil, hateth the light and cometh not to the light."

"To-day," that they might never be without hope. "Exhort one another daily," he says, "while it is called today," that is, even if a man have sinned, as long as it is "To-day," he has hope: let no man then despair so long as he lives. Above all things indeed, he says, "let there not be an evil heart of unbelief." But even suppose there should be, let no man despair, but let him recover himself; for as long as we are in this world, the "To-day" is in season...

"But exhort one another." Observe the gentleness and mildness of the expression: he said not "Rebuke," but "Exhort." Thus we are required to bear ourselves towards those who are straightened by affliction. This he says also in writing to the Thessalonians, "Warn them that are unruly", but in speaking of the feeble-minded, not so, but what? "Comfort the feeble-minded, support the weak, be patient toward all men"; that is, do not cease to hope; do not despair. For he that does not encourage one who is straightened by affliction, makes him more hardened.

"Lest any of you," he says, "be hardened by the deceitfulness of sin." He means either the deceit of the devil (for it is indeed a deceit, not to look for the things to come, to think that we are without responsibility, and that we shall not pay the penalty for our deeds here, neither will there be a resurrection); or in another sense insensibility or despairing is deceit. For to say, "What is there left? I have sinned once for all, I have no hope of recovering myself," is deceit.