In Christian theology, there is an important distinction between the doctrines of justification and sanctification. Briefly stated, justification is God’s forensic declaration that a Christian is righteous. That is to say, when God looks at the Christian, rather than seeing that individual’s own “righteousness”, God sees the imputed righteousness of Christ. Reflecting on justification often raises the question “Well, if Christians are considered righteous, then, why don’t they act like it?!” This then leads to the doctrine of sanctification. Briefly stated, sanctification is the process by which the Christian is conformed to the image of Christ and begins to imitate Christ. In other words, sanctification is the process by which the Christian is shaped into being righteous.
Conflation of these two can lead to some dangerous theology. On the one hand, one could collapse everything into sanctification and state that unless one acts perfectly, then one is not saved/justified; this is called works-righteousness and is often associated with legalism. On the other hand, one could collapse everything into justification and state that at the moment of repentance, one is more or less free to do what they want; this is equally as bad as the previous error.
Are there any parallels to this process?
Sanctification is often compared to pottery making pointing to verses like Ephesians 2:10 (Christians are the workmanship of God), Romans 9:21 (the potter is sovereign to create vessels for honourable use and dishonourable use) and many, many others. I think that another parallel can be made with mathematical approximation formulas; specifically the Taylor Series (and related Maclaurin Series). The Taylor Series can be used to approximate any function about a point in the form
f(a) + f'(a)(x-a) + [f”(a)/2!](x-a)^2 + [f”(a)/3!](x-a)^3…
Essentially, you stick a line on a point of the graph you want to approximate and then progressively get closer to the picture with each successive iteration. Now, suppose that the original function is Christ and it becomes fairly easy to see the parallel. The life of the Christian is to become a power series representation of Christ while on Earth. In other words, as the approximation line conforms to the image of the original function, Christians also conform to the image of Christ.
There are problems with this analogy as there are problems with all analogies. For example, the process of sanctification is a more involved, multifaceted process whereas the Taylor Series involves discrete succession of individual components. While sanctification is a continual, ongoing process, a Taylor Series approximation occurs in individual segments.
Monothelitism is a Christological “heresy” which states that Christ has two natures (divine and human) and one will; this is in opposition to dyotheletism which states that Christ has two natures (divine and human) and two wills (divine and human). Why the scare quotes around heresy? First, monothelitism was indeed condemned in 681 at the Third Council of Constantinople making it a formal heresy. However, from a Protestant position, these Councils, while helpful, are not authoritative. This means there is the distinct possibility for the council-members to make an error and unintentionally condemn something that’s not actually contrary to Scripture (alternatively, they could affirm something that is contrary to Scripture).
Is monothelitism an actual heresy running contrary to the fundamental teaching of Scripture? I think that it depends on the relation between will and nature. The motivation for the Third Council of Constantinople was to combat monophysitism: the teaching that Christ has one nature. This certainly is an actual heresy, running contrary to the Scriptural teaching of the hypostatic union. The truths that need to be held in balance are that (1) Christ is one person and (2) he has two natures. This is where presuppositions come into play.
There are two broad camps when it comes to the topic of will: combatibilists and libertarians. Compatibilists generally describe the will as a property of one’s nature. An individual wills to do something out of what her nature is. On the other hand, libertarians generally describe the will as a property of the person. An individual wills to do something out of who she is and not out of what she is . Libertarians would say where there is a will, there is a person (inb4 “where there’s a will there’s a way”).
Now, suppose that you’re a compatibilist and you hear that Christ has two natures; it follows naturally that Christ has two wills. If He only has one will, that would mean He only has one nature which is heretical. Suppose instead you’re a libertarian and you hear that Christ is one person; it follows quite naturally that Christ has one will. If He has two wills, that would make Him two persons which is super heretical.
In other words, monothelitism is a heresy within the compatabilist framework and dyotheletism is a heresy in the libertarian framework. It seems to me that in order to maintain monothelitism as a true heresy, one would have to demonstrate that libertarianism is incoherent in its rendering of wills as properties of persons instead of natures.
 This is not to say that libertarians deny one’s nature playing into one’s decisions. Soft libertarians posit that one’s nature provides the range or spectrum of choices available to an individual in certain circumstances but does not ultimately arbitrate which decision is made. This is in contradistinction to compatibilism which typically posits that the range of decisions consists of one member. This entire paragraph is a broad generalization and I recognize the shortcomings of its brevity.
“THE TRINITY” IS NOT IN THE BIBLE
That is to say, the word “Trinity” does not appear in the text of the Bible. The word is Latin based and is not used to describe God until around 180 AD by Theophilus of Antioch. However, this shouldn’t be of any major concern as there are many words that do not appear in the Bible, words like “rapture” and “Bible” for example. Nevertheless, we can use these words to intelligibly discuss Christian doctrine. The word “Trinity” is used to summarize the Scriptural data which testifies to the nature of God. So, using this textual fact as an argument against the validity of the Doctrine of the Trinity is rather silly.
THE TRINITY IS MONOTHEISTIC
Sometimes, the claim is made “The Trinity is wrong because the Bible says there is one God”. This is, however, not a contradiction. The Doctrine of the Trinity in its simplest form states
- There is one, and only one God
- The Father is God, the Son is God, and the Holy Spirit is God
- The Father is not the Son, the Son is not the Holy Spirit, and the Holy Spirit is not the Father
When someone says “The Bible says there is one God!” the Trinitarian will heartily agree as this is an affirmation of the first point. The distinction between the Christian Doctrine of the Trinity and say, the Islamic Doctrine of Tawhid or oneness Pentecostalism is not one of monotheism vs trithiesm; rather, it is the distinction between Unitarianism and Trinitarianism.
Unitarianism is the doctrine that the one God is one person while Trinitarianism is the doctrine that the one God is three persons. It gets to be confusing when artistic depictions of the Trinity are practically tri-theistic like this and this and this and this.