And Trypho again inquired, “But if someone, knowing that this is so, after he recognizes that this man is Christ, and has believed in and obeys Him, wishes, however, to observe these [institutions], will he be saved?
I said, “In my opinion, Trypho, such an one will be saved, if he does not strive in every way to persuade other men, —I mean those Gentiles who have been circumcised from error by Christ, to observe the same things as himself, telling them that they will not be saved unless they do so. This you did yourself at the commencement of the discourse, when you declared that I would not be saved unless I observe these institutions.”
Then he replied, “Why then have you said, ‘In my opinion, such an one will be saved,’ unless there are some who affirm that such will not be saved?”
“There are such people, Trypho,” I answered; “and these do not venture to have any intercourse1 with or to extend hospitality to such persons; but I do not agree with them. But if some, through weak-mindedness, wish to observe such institutions as were given by Moses, from which they expect some virtue, but which we believe were appointed by reason of the hardness of the people’s hearts, along with their hope in this Christ, and [wish to perform] the eternal and natural acts of righteousness and piety, yet choose to live with the Christians and the faithful, as I said before, not inducing them either to be circumcised like themselves, or to keep the Sabbath, or to observe any other such ceremonies, then I hold that we ought to join ourselves to such, and associate with them in all things as kinsmen and brethren. But if, Trypho,” I continued, “some of your race, who say they believe in this Christ, compel those Gentiles who believe in this Christ to live in all respects according to the law given by Moses, or choose not to associate so intimately with them, I in like manner do not approve of them. But I believe that even those, who have been persuaded by them to observe the legal dispensation along with their confession of God in Christ, shall probably be saved. And I hold, further, that such as have confessed and known this man to be Christ, yet who have gone back from some cause to the legal dispensation, and have denied that this man is Christ, and have repented not before death, shall by no means be saved. Further, I hold that those of the seed of Abraham who live according to the law, and do not believe in this Christ before death, shall likewise not be saved, and especially those who have anathematized and do anathematize this very Christ in the synagogues, and everything by which they might obtain salvation and escape the vengeance of fire. For the goodness and the loving-kindness of God, and His boundless riches, hold righteous and sinless the man who, as Ezekiel tells, repents of sins; and reckons sinful, unrighteous, and impious the man who fails away from piety and righteousness to unrighteousness and ungodliness. Wherefore also our Lord Jesus Christ said, ‘In whatsoever things I shall take you, in these I shall judge you.’
~Justin Martyr- Dialogues of Justin Martyr Vol. 1