The Catholic Church has defined the essential difference between the honor we give to God through prayer and the honor we give to the saints. The Second Ecumenical Council of Nicaea (787) defined the “adoration” we give to God alone as latreia (Greek) or latria (Latin).
Some Protestants, however, don’t buy this line of reasoning. They argue that this distinction is not grounded in Scripture.
Take, for example, Protestant apologist James White. In his Roman Catholic Controversy, he writes,
When we come to the New Testament . . . we discover that there is absolutely no distinction made between [dulia and latria] relevant to religious worship. As an example, we note Galatians 4:8: “However at that time, when you did not know God, you were slaves [Greek, edouleusate] to those which by nature are no gods.” But when you did not know God, you served [footnote 22: edouleusate—from douleuō, the verb form of dulia], or were slaves to, those which by nature are not gods.
Paul is speaking of the former idolatry of the Galatians. They served (dulia) idols, those which by nature are not gods at all. Are we to assume, then, on the basis of the Roman Catholic definitions, that since they only served these idols, that they were free from the charge of idolatry, since they didn’t give latria as well? Of course not! Their service of these idols was wrong whether the term latria or dulia was used. . . .
No matter how the defender of Rome tries, no basis can possibly be found in Scripture for the distinction of latria and dulia (p. 211).
One problem with White’s objection is that he seems to assume that a Catholic would deny that the Greek word edouleusate is being used in reference to the Galatians formerly worshiping idols. But that’s not the case. Catholics recognize that the service (douleia) the Galatians gave the false gods was idolatry.
The question is not whether the Greek word douleia (and the terms related to it) can be used in reference to the service or worship we give God. The question is whether douleia and latreia can be validly distinguished.
First, we may note that the Greek verb douleuō is also used in reference to human service. For example, in the Septuagint, Deuteronomy 15:18 features the verb douleuō to describe the role of a hired servant: “It shall not seem hard to you, when you let him go free from you; for at half the cost of a hired servant he has served [Greek, edouleusen] you six years.” Douleuō (and thus douleia), therefore, can represent the service of one human to another. The number of times the New Testament uses a related noun, doulos, for a human “servant” is too large to list all of them here. A simple look at a biblical concordance reveals as much (e.g., Matt. 8:9, 13:28).
So the Bible uses douleia and its related words both for service given to other humans and for service given to God or the gods.
This is true of other, related words. Consider the Greek verb proskuneō, for example, which means “to express in attitude or gesture one’s complete dependence on or submission to a high authority figure, (fall down and) worship, do obeisance to, prostrate oneself before, do reverence to.” This word is used for the worship that the twenty-four elders offer to the Lamb in Revelation 5:14. Yet it’s also used in Revelation 3:9 to refer to those of the synagogue of Satan, whom Jesus will make bow down before Christians: “I [Jesus] will make those of the synagogue of Satan . . . come and bow down [Greek, proskunēsousin] before your feet.”
What these examples reveal is that it’s not the word itself that determines whether the act of bowing is worship or not. It’s the one to whom the action is directed and the intention with which the act is being performed.
In the case of douleia, it constitutes divine worship or adoration when the object of service or honor is God, or at least what one thinks is a deity. When it’s another human, and that human is treated as such, then it’s the honor due to a creature. As seen in the case of proskuneō, if the object of the service or honor is God, then we take it to mean adoration. If it’s a creature, and the intention behind the action is creaturely honor, then it’s not adoration.
By contrast, the term latreia is used both in the Greek Old Testament and in the New Testament, where it is always used to refer to the worship of God or the gods. For example, in John 16:2, Jesus says that some who put Christians to death will think they are offering “service [latreia] to God,” and in Romans 12:1, St. Paul says we should present our bodies to God as a living sacrifice, for this “is your spiritual worship [latreia].”
As a result of this exclusive use in Scripture, latreia came to be associated closely with divine worship among Christians, whereas douleia could still be used with reference to humans. In later centuries, the Church decided to formalize this distinction and mandate that the term latreia (latria in Latin) be used for divine worship and douleia (dulia in Latin) be used for mere veneration.
This is similar to how Christians took other terms and gave them more precise meanings than they had in Scripture. For example, in later theology, terms like the elect came to refer to those people who will be saved on the Last Day. However, as Jimmy Akin explains in his book Chosen by God: God’s Elect in the Bible and Early Christian Writings, in Scripture the term had a more general meaning and referred to those who were chosen by God to have a special relationship with him—not specifically those who would be saved in the end.
Language changes over time, and situations can arise in which terms need to be given precise definitions to avoid theological confusion. When the Church needed to develop a precise way of expressing the distinction between divine worship and human veneration, it chose latreia for the former, since it was used in Scripture to express divine service, and it chose douleia for the latter, since it could refer to merely human service.
The Catholic Church, therefore, has biblical grounds for making the distinction it does between the honor given to saints (dulia in Latin) and the adoration given to God (latria in Latin). Whereas dulia can apply to the honor given to God or other entities who aren’t God, depending on the context, latria applies only to honor given to God.