St. Gregory Nazianzus in a funeral oration for his father: "Even before he was of our fold, he was ours. His character made him one of us. For, as many of our own are not with us, whose life alienates them from the common body, so, many of those without are on our side, whose character anticipates their faith, and need only the name of that which indeed they possess.”
St. Gregory of Nazianzus's father was a convert to Christianity, and St. Gregory is describing him before he converted. He says that his character ANTICIPATES his faith, and he needed ONLY THE NAME of what he indeed possessed already. This implies that his father already possessed the virtue of faith. This could only be an implicit faith, since he is speaking of before the time that he explicitly believed in Christianity. Hence his father was already implicitly a christian, and was spiritually united to the Church by charity.
(St. John Chrystostom, Homily 23 on the Acts of the Apostles) “This also Paul declaring, says, For there is no respect of persons with God. What then? Is the man yonder in Persia acceptable to Him? If he be worthy, in this regard he is acceptable, that it should be granted him to be brought unto faith. The Eunuch from Ethiopia He overlooked not. What shall one say then of the religious men who have been overlooked? It is not the case, that any (such) ever was overlooked. But what he says is to this effect, that God rejects no man.”
I intentionally chose this passage, because these kinds of statements are common in the fathers, and are often used as support for those who claim that the fathers believe explicit faith is necessary for justification.
Chrysostom explicitly brings up the case of a man in a far away country who has not heard of Christ, and asks whether he is acceptable to God. He declares that if he is worthy, than God will bring him to the faith. However, this is not to make any claims upon whether the man is able to love God and (what comes to the same thing) whether the man is justified before God. Further on in the same homily, he says:
“What then? Was He a respecter of persons beforetime? God forbid! For beforetime likewise it was just the same: Every one, as he says, that fears Him, and works righteousness, would be acceptable to Him. As when Paul says, For when the Gentiles which have not the Law, do by nature the things of the Law. That one fears God and works righteousness: he assumes both doctrine and manner of life: is accepted with Him; for, if He did not overlook the Magi, nor the Ethiopian, nor the thief, nor the harlot, much more them that work righteousness, and are willing, shall He in anywise not overlook. What say you then to this, that there are likely persons, men of mild disposition, and yet they will not believe? Lo, you have yourself named the cause: they will not. But besides the likely person he here speaks of is not this sort of man, but the man that works righteousness: that is, the man who in all points is virtuous and irreproachable, when he has the fear of God as he ought to have it. But whether a person be such, God only knows. See how this man was acceptable: see how, as soon as he heard, he was persuaded.”
Chrysostom is in the middle of a discussion concerning Cornelius here, and he relates the scripture verse which says that everyone who fears God and works righteousness is acceptable to God to the verse in Romans which says that the Gentiles who have not the law, do by nature the things of the law. He then applies this verse to both those before Christ, and those after Christ. Now, since those before Christ were justified by love of God with an implicit faith in Christ, this is already a sign that Chrysostom believes that those after Christ can also be justified by this same love of God and implicit faith. He merely believes that God will bring those people who are justified by this implicit faith to an explicit faith in Christ.
If this is not clear enough, let us look at a passage from his twentieth homily on first Corinthians.
“And yet not even love, you will say, without knowledge has any advantage. Well: this he did not say; but omitting it as a thing allowed by all, he signifies that knowledge stands in extreme need of love. For he who loves, inasmuch as he fulfils the commandment which is most absolute of all, even though he have some defects, will quickly be blest with knowledge because of his love; as Cornelius and many others. But he that has knowledge but has not love, not only shall gain nothing more, but shall also be cast out of that which he has, in many cases falling into arrogance. It seems then that knowledge is not productive of love, but on the contrary debars from it him that is not on his guard, puffing him up and elating him. For arrogance is wont to cause divisions: but love both draws together and leads to knowledge. And to make this plain he says, But if any man loves God, the same is known of Him. So that I forbid not this, says he, namely, your having perfect knowledge; but your having it with love, that I enjoin; else is it no gain, but rather loss.”
Here St. John Chrysostom explicitly says that Cornelius and many others have love first, but which then quickly leads to knowledge, i.e., explicit faith in Christianity. Thus it is clear the interpretation of the former text is quite accurate: Chrysostom believes that those who are invincibly ignorant of Christ and his Church, yet follow the law written on their hearts, may attain to love of God, which will later lead to explicit faith in Christianity.