As previously stated, no translator nor serious commentator on holy scripture denies that many times in the new testament that "the faith" refers to the object of Christian belief and not to a strictly subjective faith. Two scriptures that were cited as examples of this are these:
1) "earnestly contend for the faith which was once delivered to the saints." (Jude 1:3)
2) "shall depart from the faith, giving heed to seducing spirits, and doctrines of devils." (I Tim. 4:1)
Now let us add to this list others, beginning with a passage which most interpreters acknowledge refers to the object of Christian trust and conviction.
"And the word of God increased; and the number of the disciples multiplied in Jerusalem greatly; and a great company of the priests were obedient to the faith." (Acts 6:7)
On this verse A.T. Robertson says (emphasis mine):
"The faith (τηι πιστει — tēi pistei). Here meaning the gospel, the faith system as in Romans 1:5; Galatians 1:23; Judges 1:3, etc." (Word Pictures)
Notice how Robertson says that "the faith" denotes "the gospel" (the common interpretation), and then mentions Romans 1: 5, as another passage where "the faith" denotes the gospel and is a passage we will look at shortly as it bears on the discussion of the meaning of "the faith" in Romans 3: 3. But, first, let us look at these other verses in Acts.
"But Elymas the sorcerer (for so is his name by interpretation) withstood them, seeking to turn away the deputy from the faith." (Acts 13:8)
"Confirming the souls of the disciples, and exhorting them to continue in the faith, and that we must through much tribulation enter into the kingdom of God." (Acts 14:22)
"And so were the churches established in the faith, and increased in number daily." (Acts 16:5)
What these verses show is that Luke commonly refers to the doctrine of Christ or the gospel as "the faith" and shows that the first Christians understood what was signified and denoted by "the faith." It is as Dr. Robertson said a term that stands for the gospel system. Further, notice how the presence of the definite article is important, referring to something definite and particular. I think another word for "faith" in arthrous cases could be "creed." Thus "the faith" is "the creed." Also, we can speak of "the creed" or "the faith" without stated adjectives (or genitive nouns) because it is understood in context. It often is given with modifiers and genitive nouns and so we have "the faith (creed) of God," "the faith of saints," "the faith of Christ," etc., or put the same into this English form; "God's faith (creed)," "saint's faith," or "Christ's faith."
Though it is most often the case that where "faith" is used with the definite article it is a reference to the creed of Christians, or to the gospel revelation, or to the oracles of God in Christ, to the object of individual subjective belief, yet there are some few cases where "the faith" possibly alludes to the subjective belief of individuals. In such cases the definite article functions as a demonstrative pronoun and so in such cases the writer will indeed be speaking of the subjective faith or belief of Christians. The context will reveal this. If a writer is discussing individual belief or believing, then when in such context he says "the faith" or "the belief" he means "this belief or believing that I have been talking about." This will become evident as we look at pertinent passages, first in the Roman epistle. Further, we will see that most often when a writer is focusing on subjective belief he will do so by using "faith" (pistis) without the article, and why this is so.
Before we leave the book of Acts, let us notice this disputed passage.
"And after certain days, when Felix came with his wife Drusilla, which was a Jewess, he sent for Paul, and heard him concerning the faith in Christ." (KJV)
When Felix heard Paul "concerning the faith in Christ" we notice how the KJV adds the definite article, which is present in the Greek text. However, notice how both the NIV and NASB both omit the definite article in their translations. Others, like the KJV, retain the article.
"Several days later Felix came with his wife Drusilla, who was Jewish. He sent for Paul and listened to him as he spoke about faith in Christ Jesus." (NIV)
"But some days later Felix arrived with Drusilla, his wife who was a Jewess, and sent for Paul and heard him speak about faith in Christ Jesus." (NASB)
It is possible that the definite article means "this" or "that" and so may refer to individual Christian belief, or subjective faith, in this context. But, it is doubtful that Felix wanted to hear about Paul's personal convictions as much as his doctrine or teachings. Further, had this been the object of Felix's hearing of Paul, would not Luke had rather written that Felix sent to Paul to hear him of "your faith" (2nd person) rather than as he wrote "the faith" (3rd person)? Further, in the previous passages in Acts "the faith" stood for the Christian religion, being the oracles of God as given to the Jews as well as the oracles of God as given through Christ.
However, this verse is unique in that it does not have a genitive attached to "the faith" so as to read "the faith of..." but rather has "the faith in (eis) Christ Jesus." The Greek preposition is directional, pointing towards an object. It is belief that is towards or unto Christ. We will be looking at passages that have "the faith of Christ," but this here is "the faith towards Christ." This would seem to lend weight to the definite article being demonstrative and therefore meaning "this belief directed towards Christ Jesus." Not that this is conclusive, for even with the preposition eis, "the faith" still may denote "the Christian creed" as the other passages in Acts just noticed. Certainly the Scriptures, which are the Christian's creed, are all "unto (eis) Christ," that is, they all point to Christ.
Again, I don't think anyone can doubt that these passages in the book of Acts show that it was common nomenclature for the early church to refer to the gospel as "the faith" and these passages demonstrate such. Further, we see this same term used not only by the inspired historian but by the other writers of the new testament as we observed in Paul's first letter to Timothy and in Jude's general epistle. Shortly, we will see whether Paul used this term in his Roman epistle, and if so, where? But, let us first look at some of those other new testament passages that speak of "the faith."
"Watch, stand fast in the faith, quit yourselves like men, be strong." (I Cor. 16:13)
"Examine yourselves, whether you are in the faith." (II Cor. 13:5)
"But they had heard only, That he who persecuted us in times past now preaches the faith which once he destroyed." (Gal. 1:23)
"If you continue in the faith grounded and settled, and do not be moved away from the hope of the gospel, which you have heard, and which was preached to every creature which is under heaven; of which I Paul am made a minister." (Col. 1:23)
"Being rooted and built up in him, and confirmed in the faith, as you have been taught, abounding in it with thanksgiving." (Col. 2:7)
"But if any does not provide for his own, and specially for those of his own house, he has denied the faith, and is worse than an unbeliever." (I Tim. 5:8)
"For the love of money is the root of all evil: which while some coveted after, they have erred from the faith, and pierced themselves through with many sorrows." (I Tim. 6:10)
"Which some professing have erred concerning the faith." (I Tim. 6:21)
"Now as Jannes and Jambres withstood Moses, so do these also resist the truth: men of corrupt minds, reprobate concerning the faith." (II Tim. 3:8)
"I have fought a good fight, I have finished my course, I have kept the faith." (II Tim. 4:7)
"This witness is true. Therefore rebuke them sharply, that they may be sound in the faith." (Titus 1:13)
"My brothers, do not have the faith of our Lord Jesus Christ, the Lord of glory, with respect of persons." (James 2:1)
"Whom resist steadfast in the faith, knowing that the same afflictions are accomplished in your brothers that are in the world." (I Peter 5:9)
"Here is the patience of the saints: here are those who keep the commandments of God, and the faith of Jesus." (Rev. 14:12)
I doubt that anyone will doubt the frequency of the term "the faith" in the new testament scriptures and that it refers to the object of Christian conviction, or to their scriptures or creed. But, let us notice this interesting passage that also has "the faith."