Irenaeus — Against Heresies 4.37.5
If it were not in our power to do these things or not to do them, what point would there be in counsel from the apostle — and much more from the Lord himself — to do some things and abstain from others?
But because man has been of free decision from the beginning, and God — whose likeness he bears — is of free decision, counsel is always given him to hold to the good, which is completed in obedience to God. And not only in works but also in faith has the Lord preserved man’s free decision and his power under his own control, saying, “According to your faith be it done to you,” showing that a person’s faith is his own, because he has his own judgment.
Again: “All things are possible to the one who believes,” and, “Go; as you have believed, be it done to you.” All such things show that man is under his own power according to faith. On this account the one who believes has eternal life, and the one who does not believe the Son does not have eternal life, but the wrath of God remains on him.
On this reasoning, showing his own good and marking man as of his own decision and under his own power, the Lord said to Jerusalem: “How often I wanted to gather your children as a hen gathers her chicks under her wings, and you would not! Therefore your house is left to you desolate.”
Latin
Si igitur non in nobis esset facere haec, aut non facere, quam causam habebat Apostolus, et multo prius ipse Dominus, consilium dare, quaedam quidem facere, a quibusdam vero abstinere? Sed quoniam liberae sententiae ab initio est homo, et liberae sententiae est Deus cuius ad similitudinem factus est, semper consilium datur ei continere bonum, quod perficitur ex ea quae est ad Deum obedientia. Et non tantum in operibus, sed etiam in fide, liberum et suae potestatis arbitrium hominis servavit Dominus, dicens: Secundum fidem tuam fiat tibi; propriam fidem hominis ostendens, quoniam propriam suam habet sententiam. Et iterum: Omnia possibilia credenti; et, Vade, sicut credidisti, fiat tibi. Et omnia talia suae potestatis secundum fidem ostendunt hominem. Et propter hoc, is qui credit et habet vitam aeternam: qui autem non credit Filio, non habet vitam aeternam, sed ira Dei manebit super ipsum. Secundum hanc igitur rationem, et suum proprium bonum ostendens Dominus, et sui arbitrii ac suae potestatis hominem significans, dicebat ad Hierusalem: Quoties volui congregare filios tuos, quemadmodum gallina pullos suos sub ascellas, et noluisti? Quapropter relinquetur vobis domus vestra deserta.