Scripture calls Christians to “Test all things; hold fast what is good.” (1 Thessalonians 5:21 NKJV). This is important when we come to the doctrines of the Christians faith, since scripture warns that there are many false teachers and antichrists who have gone forth teaching false doctrine, twisting the scriptures to their own destruction (1 John 2:18-22).
In the face of so many false teachers, it is important to see every point of doctrine proven from scripture before we believe it, in order to have certainty regarding every point of doctrine, rather than merely being carried away with strange theories, mere probabilities, and false teachings.
On this subject, fourth century church father Cyril Archbishop of Jerusalem said:
“Have thou ever in thy mind this seal, which for the present has been lightly touched in my discourse, by way of summary, but shall be stated, should the Lord permit, to the best of my power with the proof from the Scriptures. For concerning the divine and holy mysteries of the Faith, not even a casual statement must be delivered without the Holy Scriptures; nor must we be drawn aside by mere plausibility and artifices of speech. Even to me, who tell thee these things, give not absolute credence, unless thou receive the proof of the things which I announce from the Divine Scriptures. For this salvation which we believe depends not on ingenious reasoning, but on demonstration of the Holy Scriptures.”
It is necessary then, to have clear demonstration form the scriptures on every point of doctrine, so that we have a sure and true knowledge of what is true.
In the Protestant tradition, this idea is greatly emphasized as part of doctrine of Sola Scriptura. Protestantism broke with the Roman Catholic church in large part over the doctrines regarding how a person is saved and brought into fellowship with God (this area of doctrine is called soteriology).
Protestants disagreed with the Roman Catholic Church’s teaching on soteriology because they saw that it was contrary to what scripture teaches. They examined the Roman doctrines on the basis of scripture, and found that they contradicted them. So they instead sought to articulate what scripture teaches on soteriology as accurately as possible.
This caused a great deal of controversy. In the midst of this controversy, a great deal of work was put into how to best and most accurately articulate soteriology. Hundreds of well-known theologians of the sixteenth and seventeenth centuries expended a great deal of energy to articulate these doctrines in an extremely detailed and thorough way. To this day, as a result, many modern Protestants are still very articulate in this area of doctrine. Even those who are largely untrained in theology and doctrine are often able to articulate soteriology in some detail, and are able to distinguish between their own understanding of it and the Roman Catholic position.
The outlook of critically examining what is being said on the topic of soteriology in order to avoid accepting false teaching that cannot be proven from scripture is a common one among believing Protestants. This is in large part because the doctrinal truths regarding how a person is reconciled to God are recognized as being extremely important, and that importance leads people to take the issue seriously and not just accept anything they hear without seeing actual proof from scripture.
This attitude is largely non-existent, however, in regards to the doctrines pertaining to the Trinity. This is unfortunate because these doctrines are foundational even to soteriology itself. Rejection of them constitutes a rejection of Christianity. What is at the core of what is being dealt with in trinitarian doctrine is the very identities of the persons of God, His Son, and His Holy Spirit. Who is the God we are reconciled to and forgiven our sins by in the gospel? Who is the Lord Jesus Christ through Whom we have this salvation? Who is the Spirit Christians are sealed with? It is these questions that are ultimately at stake in trinitarian doctrine.
Christians need to strive to have an attitude that is more obedient to the scripture’s command to “test everything, and hold fast that which is good” in respects to the doctrine of the Trinity. Too often it seems like the attitude people take towards trinitarian doctrine is far different than that they have towards soteriology. Unlike soteriology, trinitarian doctrine is regarded as something esoteric and mysterious, to be accepted from trustworthy teachers without question or criticism- without discernment. This opens the door to receiving false teaching, intentional and otherwise. Just as many recognize a need to exercise careful discernment in respect to the gospel, lest they believe a false gospel, so we must also exercise discernment in respect to the doctrine of the Trinity, lest we find ourselves believing a false doctrine of the Trinity.
Just as it is not sufficient for us to believe a point of doctrine related to soteriology that a notable and respected theologian has taught without also critically examining what is being taught and making sure it can be proven from scripture, so also we need to do more than just ‘take Augustine’s word for it’ with respect to the Trinity. The fact that men like Augustine, Calvin, and Van Til have said or not said something on any point of doctrine does nothing to make that point of doctrine true or false. Even the godliest, wisest, most intelligent men err. No amount of good intentions makes it impossible to make an honest mistake, or to misunderstand something. We need to be willing to do the work of looking critically at what theologians tell us about the doctrine of the Trinity- and only accepting that which we see truly proven from the scriptures. Without a critical attitude on these doctrines, we open ourselves up to adopt all the errors and mistakes of those we learn from, in addition to all they teach correctly.