Psalms 139:4

Accordingly it is patience which is both subsequent and antecedent to faith. In short, Abraham believed God, and was accredited by Him with righteousness; but it was patience which proved his faith, when he was bidden to immolate his son, with a view to (I would not say the temptation, but) the typical attestation of his faith. But God knew whom He had accredited with righteousness. So heavy a precept, the perfect execution whereof was not even pleasing to the Lord, he patiently both heard, and (if God had willed) would have fulfilled. …

5. “Who have imagined unrighteousnesses in their heart” ( ver. 2 ).…From them free me, from them let Thy hand be most powerful to deliver me. For easy is it to avoid open enmities, easy is it to turn aside from an enemy declared and manifest, while iniquity is in his lips as well as his heart; he is a troublesome enemy, he is secret, he is with difficulty avoided, who beareth good things in his lips, while in his heart he concealeth evil things. “All the day long did they make war.” What is, “war”? They made for me what I was to fight against all the day. For from thence, from such hearts as these, ariseth all that the Christian fighteth against. …

6. From these animals Christ also instructs us, when He says, “Be ye wise as serpents, and harmless as doves.” And again; “Behold the fowls of the air, for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them.” The prophet also, to shame the ungrateful Jews, thus speaks; “The ox knoweth his owner, and the ass his master’s crib; but Israel doth not know me.” And again; “The turtle and the swallow and the crane observe the time of their coming, but my people knoweth not the judgment of the Lord his God.” From these animals, and such as these, learn to achieve virtue, and be instructed to avoid wickedness by the contrary ones. For as the bee followeth good, so the asp is destructive. Therefore shun wickedness, lest thou hear it said, “The poison of asps is under their lips.” Again, the dog is devoid of shame. …

But if any felt displeased that I have called the mouths of the multitude ditches of some mire, let him know that I have said it, sparing them very much. For Scripture hath not used this measure, but a comparison far stronger. “For adder’s poison,” it is said, “is under their lips,and their throat is an open sepulchre.” But theirs are not so, but full of much fragrance.

6. For the heretics, who are most profane in all things, have sharpened their tongue against the Holy Ghost also, and have dared to utter impious things; as Irenæus the interpreter has written in his injunctions against heresies. For some of them have dared to say that they were themselves the Holy Ghost; of whom the first was Simon, the sorcerer spoken of in the Acts of the Apostles; for when he was cast out, he presumed to teach such doctrines: and they who are called Gnostics, impious men, have spoken other things against the Spirit, and the wicked Valentinians again something else; and the profane Manes dared to call himself the Paraclete sent by Christ. Others again have taught that the Spirit is different in the Prophets and in the New Testament. Yea, and great is their error, or rather their blasphemy. …

79. Would that it were merely empty! And now may their blasphemy fall upon the head of the ungodly! All fear has been banished from souls, shamelessness has taken its place, and knowledge and the deep things of the Spirit are at the disposal of anyone who will; and we all become pious by simply condemning the impiety of others; and we claim the services of ungodly judges, and fling that which is holy to the dogs, and cast pearls before swine, by publishing divine things in the hearing of profane souls, and, wretches that we are, carefully fulfil the prayers of our enemies, and are not ashamed to go a whoring with our own inventions. Moabites and Ammonites, who were not permitted even to enter the Church of the Lord, frequent our most holy rites. …

There are some “in sheep’s clothing, but inwardly they are ravening wolves:” whom we know by their fruit. These men seem indeed at first to be of us, but they are not of us: “for if they had been of us, they would no doubt have continued with us.” But when they have spewed out their impiety, throwing out the guile that is in them, and seizing the weaker ones, and those who have their senses unpractised in the divine utterances, they carry them along with themselves to destruction, wresting and doing despite to the Fathers’ doctrines, just as they do the Holy Scriptures also to their own destruction: whom we must be forewarned of and take heed lest some should be misled by their wickedness and shaken in their firmness. “For they have sharpened their tongues like serpents: adder’s poison is under their lips,” as the prophet has cried out about them.