Question 22. What is then necessary for a christian to believe?

Answer: All things promised us in the gospel, (a) which the articles of our catholic undoubted christian faith briefly teach us.

Question 23. What are these articles?

Answer: 1. I believe in God the Father, Almighty, Maker of heaven and earth: 2. And in Jesus Christ, his only begotten Son, our Lord: 3. Who was conceived by the Holy Ghost, born of the Virgin Mary: 4. Suffered under Pontius Pilate; was crucified, dead, and buried: He descended into hell: 5. The third day he rose again from the dead: 6. He ascended into heaven, and sitteth at the right hand of God the Father Almighty: 7. From thence he shall come to judge the quick and the dead: 8. I believe in the Holy Ghost: 9. I believe a holy catholic church: the communion of saints: 10. The forgiveness of sins: 11. The resurrection of the body: 12. And the life everlasting.

…

Question 59. But what does it profit thee now that thou believest all this?

Answer: That I am righteous in Christ, before God, and an heir of eternal life. (a)

Question 60. How are thou righteous before God?

Answer: Only by a true faith in Jesus Christ; (a) so that, though my conscience accuse me, that I have grossly transgressed all the commandments of God, and kept none of them, (b) and am still inclined to all evil; (c) notwithstanding, God, without any merit of mine, (d) but only of mere grace, (e) grants and imputes to me, (f) the perfect satisfaction, (g) righteousness and holiness of Christ; (h) even so, as if I never had had, nor committed any sin: yea, as if I had fully accomplished all that obedience which Christ has accomplished for me; (i) inasmuch as I embrace such benefit with a believing heart. (j)

Thus teaches the Heidelberg Catechism. How different this is when we compare it to the words of the highly respected nineteenth-century Presbyterian church historian, William Cunningham:

I think it is much to be regretted that so very inadequate and defective a summary of the leading principles of Christianity as the Apostles’ Creed—possessed of no authority, and having no extrinsic claims to respect—should have been exalted to such a place of prominence and influence in the worship and services of the church of Christ; and I have no doubt that this has operated injuriously in leading to the disregard of some important articles of Christian doctrine, which are not embodied in it, but which are of fundamental importance. Even in the third century, we find the doctrines of grace—the true principles of the Gospel which unfold the scriptural method of salvation, were thrown into the background, were little attended to, and not very distinctly understood; while the attention of the church in the fourth century was almost entirely engrossed by controversial speculations about the Trinity and the person of Christ; and it is, I believe, in some measure from the same cause—i.e., having the Apostles’ Creed pressed upon men’s attention in the ordinary public services of the church, as a summary of Christian doctrine, entitled to great deference and respect—that we are to account for the ignorance and indifference respecting the great principles of evangelical truth by which so large a proportion of the ordinary attenders upon the services of the Church of England have been usually characterized—a result aided, no doubt, by the peculiar character and complexion of the other two creeds which are also sanctioned by her articles, and which are sometimes, though not so frequently, used in her public service—the Nicene and the Athanasian.

Since William Cunningham was famous as a Church historian, his statements were not a secret but were widely read–as far as I know with general approval. What a huge difference! The Heidelberg Catechism defines the promises of the Gospel as the content of the Apostles Creed and then teaches that anyone who believes these promises is righteous before God. That is justification by faith, not the content of the Gospel, but the result of believing it.

The Heidelberg Catechism is a sixteenth-century document, while Cunningham is nineteenth. But we can narrow the time gap a bit. Consider the witness of Francis Turretin the world renown Reformed Theologian of the seventeenth century, he asks in his Institutes of Elenctic Theology,

Is the true Church indefectible, which always was and always ought to be in the world until the consummation of the ages? We affirm against the Socinians.

In elaboratingon this claim, Turretin asks another one: “Where was our church before Luther and Zwingli and how was it preserved?” Turretin is typically thorough and gives several lines of argument. Partially, he answers that

our church was in the papacy itself, inasmuch as God always preserved in the midst of Babylon a remnant for himself according to the election of grace (to with, true believers who, groaning under that captivity, panted for spiritual deliverance; who are said to have been in the papacy not as to communion with it [since they disapproved of and turned away from its errors and superstitions], but as to tarrying and as guests because they lived in the midst of the papal church, not conjointly, but scattered through kingdoms, provinces, cities and families, in which God wonderfully preserved his people) (v. 3, p. 61).

This leads to more arguments and explanations. Here is the one that is relevant to William Cunningham’s verdict regarding the Apostles Creed: Turretin states that, “by the providence of God the principal heads of religion were comprehended in the Apostles’ Creed, the Decalogue, the Lord’s prayer, and the sacraments” (p. 65).

Turretin later elaborates on the value of the Apostles’ Creed, saying

Although the church which was in the papacy before the Reformation did not have among the articles of its faith justification by faith alone, the rejection of all sensible sacrifices beside the sacrifice of Christ and the repudiation of the worship of images and of the invocation of the saints and other articles (concerning which there is controversy between us), it does not follow that believers did not have in the doctrine received for that time the necessary food for salvation. Such articles are not positive and affirming, containing things that are to be believed and done, in which therefore the essence of faith and religion consists, but negatively and excluding the errors which ought to be rejected, which do not pertain to the building up of faith. As no one would put down among nourishments the care of avoiding poisons which could produce death, so the positive articles work salvation properly, while the negative only remove those things which can interfere with salvation.

Although it is impossible for one to work out his salvation under a Socinian ministry (because it formally and directly destroys the foundation of Christianity by denying the mystery of the Trinity and of the divinity of Christ and of the truth of his satisfaction), it ought not to be said that it was equally impossible to live under the papal ministry, although corrupted in a different way… (v. iii, pp. 67, 68).

To my mind this is an immense contrast. On the one hand, according to Turrettin, the articles of the Apostles’ Creed are “the essence of faith and religion,” and “nourishments” that “pertain to the building up of faith.” On the other hand, for Cunningham, the Apostles’ Creed is virtually useless–only encouraging fruitless Trinitarian and Christological speculation in the Early Church and led to the neglect of “the true principles of the Gospel which unfold the scriptural method of salvation.”

So somehow there was a switch. It is true, of course, that Protestants have always considered justification by faith alone a vital matter. But it was later when it became equated with the very content of the gospel so that anyone who did not affirm this doctrine could be consigned to a place outside Christ’s kingdom.