He also explains that faith in Christ was always necessary as far as substance, only that the articles to be believed explicitly increased.
Among men the same things were always to be hoped for from Christ. But as they did not acquire this hope save through Christ, the further they were removed from Christ in point of time, the further they were from obtaining what they hoped for. Hence the Apostle says (Hebrews 11:13): “All these died according to faith, not having received the promises, but beholding them afar off.” Now the further off a thing is the less distinctly is it seen; wherefore those who were nigh to Christ’s advent had a more distinct knowledge of the good things to be hoped for.
(ST II-II.1.7, ad. 1)
He explains how as revelation increased, faith in Christ grew more and more explicit.
As stated above (5; 1, 8), the object of faith includes, properly and directly, that thing through which man obtains beatitude. Now the mystery of Christ’s Incarnation and Passion is the way by which men obtain beatitude; for it is written (Acts 4:12): “There is no other name under heaven given to men, whereby we must be saved.” Therefore belief of some kind in the mystery of Christ’s Incarnation was necessary at all times and for all persons, but this belief differed according to differences of times and persons. The reason of this is that before the state of sin, man believed, explicitly in Christ’s Incarnation, in so far as it was intended for the consummation of glory, but not as it was intended to deliver man from sin by the Passion and Resurrection, since man had no foreknowledge of his future sin. He does, however, seem to have had foreknowledge of the Incarnation of Christ, from the fact that he said (Genesis 2:24): “Wherefore a man shall leave father and mother, and shall cleave to his wife,” of which the Apostle says (Ephesians 5:32) that “this is a great sacrament . . . in Christ and the Church,” and it is incredible that the first man was ignorant about this sacrament.
But after sin, man believed explicitly in Christ, not only as to the Incarnation, but also as to the Passion and Resurrection, whereby the human race is delivered from sin and death: for they would not, else, have foreshadowed Christ’s Passion by certain sacrifices both before and after the Law, the meaning of which sacrifices was known by the learned explicitly, while the simple folk, under the veil of those sacrifices, believed them to be ordained by God in reference to Christ’s coming, and thus their knowledge was covered with a veil, so to speak. And, as stated above (Question 1, Article 7), the nearer they were to Christ, the more distinct was their knowledge of Christ’s mysteries.
After grace had been revealed, both learned and simple folk are bound to explicit faith in the mysteries of Christ, chiefly as regards those which are observed throughout the Church, and publicly proclaimed, such as the articles which refer to the Incarnation, of which we have spoken above (Question 1, Article 8). As to other minute points in reference to the articles of the Incarnation, men have been bound to believe them more or less explicitly according to each one’s state and office.
(ST II-II.2.7, co.)
If this is all more or less agreeable, we have enough to work with to say a little about the prospect of the salvation for Jews. It is perhaps possible for a Jew today to have faith in Christ in a less explicit manner than we do because of limited revelation although this is complicated by the presence of the Church. If he has believed in what has been revealed by God to him according to his ability, it would make sense that he could be saved. On the other hand, Judaism today is such a diverse phenomenon. Furthermore, as far as I know, Judaism today is very different from Judaism (if you can call it that) at the time of people like Abraham or Moses, so it is impossible to say that Jews by virtue of their religion have the same faith as the Patriarchs. And it is even further complicated by the fact that Jews as a general rule not only do not have explicit faith in Christ, but explicitly deny him. I would say that the salvation of Jews (as a religious designation) would have to be an exceptional case rather than something to be taken for granted.
