Why Do Theologians Use Greek and Latin Technical Terms?

Question 57.

Theological vocabulary can feel deliberately designed to shut ordinary believers out, homoousios, hypostatic union, propitiation, sanctification, a wall of unfamiliar words standing between you and a faith that Jesus taught largely through simple stories about farmers, fishermen, and lost sheep. It is a completely reasonable frustration, and I do not want to wave it away. But these technical terms did not appear because theologians enjoy sounding clever. Almost every one of them was coined at a specific historical moment to solve a genuine communication problem that plain, everyday language could not solve accurately enough on its own.

I want to explain why theological vocabulary developed the way it did, what real problem each technical term was actually built to solve, and how to hold this specialised language without letting it become a barrier between you and Scripture itself.

Precision Was the Original Problem

Ordinary language is wonderfully flexible, but that flexibility becomes a liability the moment a genuinely subtle distinction needs to be stated with total precision. When the fourth century church needed to say exactly how the Father and the Son could both be fully God while remaining genuinely one God rather than two separate gods, everyday Greek words kept sliding in meaning depending on who used them and how. The technical term homoousios, of the same essence, was coined specifically because the available ordinary vocabulary could not pin the distinction down precisely enough to exclude both of the two major errors on either side. A specialised term, once carefully defined, holds still in a way ordinary language often cannot, and that stability is exactly what a precise doctrinal boundary requires.

Technical Terms Compress Whole Arguments

A word like propitiation compresses an entire argument about the cross into a single term, that Christ’s death satisfied God’s righteous response to sin rather than simply demonstrating love or setting a moral example, a distinction that matters enormously once you notice how differently the atonement gets described once that single word is removed from the conversation. Unpacking everything that single word carries would take several paragraphs of plain English every single time the concept came up, which would make sustained theological argument practically impossible. Once a term like this is properly learned, it functions as useful shorthand, letting a writer or preacher reference a whole developed idea in a single word rather than rebuilding the entire argument from scratch in every sentence. This is not so different from how any specialised field, medicine, law, engineering, develops its own vocabulary for exactly the same reason.

Why Latin and Greek Specifically

Greek dominates the earliest technical vocabulary because the New Testament itself was written in Greek, and the great councils that hammered out terms like homoousios and hypostasis were conducted in a Greek-speaking world. Latin dominates a later layer of vocabulary because the Western church subsequently did much of its theological work in Latin, giving us terms like justification, sanctification, and propitiation, all derived from Latin roots even though the underlying concepts are thoroughly biblical. Neither language carries any special spiritual authority over English or any other tongue. They simply happen to be the languages in which particular doctrinal battles were fought and settled, leaving their vocabulary embedded in theology much the way legal English still carries inherited Latin terms like habeas corpus, useful shorthand surviving from the era when the relevant arguments actually took place.

The Genuine Risk of Theological Vocabulary

The real danger is not the vocabulary itself but the temptation to use it as a substitute for actual understanding, deploying an impressive term without being able to explain plainly what it means or why it matters. A believer who can say propitiation but cannot explain in ordinary words what happened at the cross has learned a password rather than a truth. The goal of learning theological vocabulary is always to deepen genuine comprehension, never to create an in-group of people who sound educated while leaving everyone else feeling excluded. Sound teaching translates technical terms back into plain language as a matter of course, precisely so the underlying doctrine remains accessible to the newest believer in the congregation rather than reserved for those with formal training.

How to Actually Learn This Vocabulary Well

The most reliable way to learn theological vocabulary is always to pair the technical term with its plain English explanation every single time you encounter it, rather than memorising definitions in isolation. When this site introduces a term like homoousios or discusses the distinction between orthodoxy and orthopraxy, the goal is always to explain the plain meaning first and treat the technical label as a convenient handle attached afterward, not the other way around. Over time, hearing a term used correctly and explained clearly enough times will make the vocabulary feel like a natural part of how you think about Scripture rather than an intimidating foreign language layered on top of it.

It is worth adding that you do not need to master this vocabulary before you can genuinely understand or benefit from sound doctrine. Millions of faithful believers across church history, illiterate in Greek and Latin alike, have held a genuine, saving grasp of the gospel without ever learning a single technical term. The vocabulary exists to help careful teachers and writers communicate with precision to one another and to students who want to go deeper, not to gatekeep the faith itself. Approach unfamiliar terms with curiosity rather than intimidation, and treat every one you learn as a small tool added to your kit rather than a hurdle standing between you and genuine understanding. Curiosity, patiently sustained over months rather than forced in a single sitting, will get you further than any amount of anxious cramming ever could.

A further encouragement is worth adding for readers who feel they are starting from nothing. Nobody is born already fluent in theological vocabulary, and every seminary graduate you admire once encountered these same words for the first time and had to look them up. Keep a simple list of unfamiliar terms as you read, look each one up when you have a moment, and revisit the list occasionally. Within a year of steady, unhurried reading, most of the vocabulary that currently feels foreign will have quietly become part of your ordinary working knowledge, absorbed gradually rather than crammed all at once, the same way a child raised in a bilingual household absorbs a second language without ever sitting down for a single formal lesson.

It is worth pausing on one further example to see the pattern clearly. The word Trinity itself never appears anywhere in Scripture, a fact sceptics sometimes raise as though it settled the matter against the doctrine. But absence of the label is not absence of the substance. Scripture repeatedly presents the Father as God, the Son as God, and the Spirit as God, while insisting throughout that there is only one God, and the church eventually needed a single convenient word to refer to that whole scriptural pattern without restating all the relevant texts every time the subject arose. Trinity, from the Latin trinitas, simply means threeness, a plain label attached to a thoroughly biblical pattern rather than a foreign concept smuggled in from outside Scripture. The word is not inspired. The pattern it names certainly is, which is exactly the distinction worth holding onto whenever someone objects to a doctrine on the grounds that its technical label cannot be found printed on the page of Scripture itself.

A similar pattern holds for the word Bible itself, which comes from the Greek biblia, simply meaning books, and for canon, from a Greek word meaning a measuring rod or standard. Neither term appears in Scripture describing itself this way, yet both have become indispensable shorthand for referring to the collection of divinely inspired books as a single, bounded whole. Recognising that even the most basic vocabulary Christians use every day, Bible, canon, Trinity, developed the same way as more obviously technical terms like homoousios or propitiation helps put the whole question of theological vocabulary in proper perspective. Every generation of the church has needed new words for old, thoroughly biblical realities, and there is nothing suspicious or illegitimate about that ongoing process continuing today.

So, now what?

The next time you meet an unfamiliar theological term, resist both extremes, neither dismissing it as needless jargon nor treating it as a password you must master before you can genuinely belong. Ask what plain, ordinary problem the term was actually built to solve, learn the plain English explanation alongside the technical label, and let the vocabulary serve your understanding of Scripture rather than standing in front of it. Theological vocabulary, rightly used, exists to help you say true things about God with greater precision, not to keep you at arm’s length from Him.

For if the bugle gives an indistinct sound, who will get ready for battle? So with yourselves, if with your tongue you utter speech that is not intelligible, how will anyone know what is said?

1 Corinthians 14:8-9, ESV