In this post, I will interact with the comments of John Calvin (1509-1564), one of the leading figures in the Protestant reformation where he attempts to support forensic justification from 1 Tim 3:16, which highlights the problems found within most of Protestant works, whether apologetic or scholarly, on this issue.
1 Tim 3:16 reads as follows in the NRSV:
Without any doubt, the mystery of our religion is great: He was revealed in the flesh, vindicated in spirit, seen by angels, proclaimed among the nations, Believed on the world, taken up to glory.
(To see a previous post refuting the claim this verse "proves" Trinitarian Christology, see here)
The section in bold translates the Greek term ἐδικαιώθη ἐν πνεύματι which can alternatively be rendered "justified in the Spirit," as one finds in the KJV.
In his commentary on this verse, Calvin wrote:
Justified in the Spirit. As the Son of God "emptied himself," (Php 2:7), by taking upon him our flesh, so there was displayed in him a spiritual power which testified that he is God. This passage has received various interpretations; but, for my own part, satisfied with having explained the Apostle’s real meaning, as far as I understand it, I shall add nothing more. First, justification here denotes an acknowledgment of divine power; as in Ps 19:9 where it is said, that
"the judgments of God are justified,"
that is, are wonderfully and absolutely perfect; and in Ps 51:4, that "God is justified," meaning that the praise of his justice is illustriously displayed. So also, (Mt 11:19, and Lu 7:35,), when Christ says, that
"Wisdom hath been justified by her children,"
he means that they have given honor unto her; and when Luke (Lu 7:29) relates that the publicans "justified God," he means that they acknowledged, with due reverence and gratitude, the grace of God which they beheld in Christ. What we read here has, therefore, the same meaning as if Paul had said, that he who appeared clothed with human flesh was, at the same time, declared to be the Son of God, so that the weakness of the flesh made no diminution of his glory.
Under the word Spirit, he includes everything in Christ that was divine and superior to man; and he does so for two reasons: First, because he had been humbled in "the flesh," the Apostle now, by exhibiting the illustration of his glory, contrasts "the Spirit" with "the flesh." Secondly, that glory, worthy of the only-begotten Son of God, which John affirms to have been seen in Christ, (Joh 1:14), did not consist in outward display, or in earthly splendor, but was almost wholly spiritual. The same form of expression is used by him, (Ro 1:3-4),
"Who was made of the seed of David according to the flesh, and declared by the power of the Spirit to be the Son of God;"
but with this difference, that in that passage he mentions one kind of manifestation, namely, the resurrection.
We can see how desperate Calvin is to force forensic justification into (1) this verse and (2) the cognate terms for δικαιοω.
Firstly, texts such as Psa 19:9 are not soteriological in nature.
Secondly, notice that Psa 19:9 and other like-verses actually refute Calvin's soteriology. How? In Reformed theology, justification is a legal declaration wherein one is declared "justified" or "righteous" based, not on an intrinsic or infused righteousness, but an imputed/alien righteousness--that is, the person is not actually righteous/justified, whence Luther's "simul iustus et peccator" (sinful and just at the same moment). However, God's judgments are not merely "declared" righteous, they truly are righteous. Indeed, this leads to a problem that permeates much of Protestantism--an "either-or" fallacy; just as Protestants are "either-or" with respect to faith and works, they are "either-or" with respect to the meaning of δικαι-terms--it is either a legal declaration or something infused or intrinsic within the person (and the latter is always precluded)--it can be both, depending on the context. Indeed, even in contexts in both the OT and NT where the term is used in a legal context, it never means anything near the legal fiction meaning Protestant theology calls for (see this post discussing Lev 17:3-4 and Deut 25:1).
Thirdly, with respect to Matt 11:19 and its parallel in Luke 7:35, it is true that δικαιοω is used in a sense of "vindication." However, it is being used as a metaphor and, furthermore, is not being used in a soteriological context. It is only because the context of these verses does not concern themselves with justification and related issues. Something similar happens in English--if you refer to your wife as "the apple of my eye," such clearly uses "apple" in a metaphorical sense, not the "normative" sense of "apple"--to claim otherwise would result in utter inanity! Obviously, "wisdom" cannot be justified in a soteriological sense, as it is a virtue, so "justified" changes from its "normative" meaning to be accommodated to the metaphorical context it is used in.
As for 1 Tim 3:16 itself, such proves too much, as it shows that δικαιοω has, not just a legal/declarative meaning, but also a transformative meaning. As previously mentioned, the underlining Greek translated as “vindicated” is ἐδικαιώθη, the indicative aorist passive of the verb δικαιοω. While one can (correctly) argue that δικαιοω has the meaning of "vindicated," it also shows that the verb also have a transformative sense too, by the mere fact that Christ in His resurrection was literally transformed from a state of death to a state of life.
While much more could be said, it is rather clear that the interpretation of 1 Tim 3:16 and the nature of justification by Calvin, which is followed by many modern Calvinists, rests on lousy exegetical skills in order to provide biblical support for forensic justification.