KJV Acts 20:28 reads as follows:
“Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood.”
Translations seem to be about evenly divided between those that read at the end of the verse something like the KJV’s “with his own blood” and those that read something like “with the blood of his son.” Trying to determine the better reading is an interesting exercise that involves textual criticism, grammar and theology. First I will lay out the possibilities, then I will discuss them, finally indicating where I would come down on this question.
The critical part of the verse for our purposes is the end, which reads in the KJV “the church of God, which he hath purchased with his own blood.” There are two related variants in close succession here. First, we have the following choices:
1. of God
2. of the Lord
3. of the Lord, even God
4. of the Lord God
5. of the Lord Jesus
6. of the Lord Christ
7. of Christ
Readings three through seven are found mainly in the Byzantine manuscript tradition and certain Church Fathers, and are obvious conflations of the two main choices, readings one and two.
Second, we also have the following choices:
1. with his own blood or with the blood of his own
2. with his own blood
Reading 1 is ambiguous and can be interpreted either way; reading two is not ambiguous. The Greek for reading 1 is dia tou haimatos tou idiou. The word dia is the preposition “through, with,” which with this meaning takes a genitive. The word tou is the definite article “the” in the genitive case, and haimatos is the word for blood, also in the genitive case. The word idiou means “(one’s) own,” which is also in the genitive case. The pattern article + noun + article + adjective, where the noun and the adjective agree in number, case and gender, is one way of expressing the adjective attributively. Thus, these words could be translated “with his own blood,” where “own” is an attributive adjective modifying “blood.”
On the other hand, idiou with the article could be taken as a substantive, meaning that even though it is an adjective it is used as if it were a noun. The word “good” is an adjective in English, but in the expression “the good, the bad and the ugly” it is used substantively. This reading would result in the translation “with the blood of his own one.” This is bad English and is usually understood as a reference to his own son.
Reading 2, which is dia tou haimatos, lacks this ambiguity. The pattern article + adjective + noun is the other common way to express an attributive adjective, but with this wording the substantive reading is not possible, and the words would have to be translated something like “with his own blood.”
As for theology, the translation “the church of God, which he hath purchased with his own blood,” is awkward, because usually the word “God” [theos] in the New Testament is a reference to God the Father, not to Jesus Christ, but it was Jesus who bled for us. Does God have blood? On the other hand, the translation “the church of God, which he hath purchased with the blood of his own [son]” might seem to some to be at variance with orthodox trinitarian perceptions. (I do not think this is necessarily the case myself, but I have seen indications of some discomfort with it on this ground in the literature.)
With the problem laid out, let us return to the textual question. The textual evidence between “God” and “Lord” is virtually even, so the question will have to be addressed based on other factors. The basic argument of those who defend “church of the Lord” is that that is the rarer expression, appearing but seven times in the Septuagint and not at all in the New Testament, whereas “church of God” occurs 11 times in the Pauline epistles. Thus, a scribe might have seen “church of the Lord” and changed the rare expression to the more common “church of God.”
The more difficult reading, however, is “church of God,” because of the awkwardness of the following reference to “his own blood.” The suggestion that God has blood may have led scribes to replace “God” with the more generic “Lord,” which could more readily be interpreted as a reference to Jesus. (For a more detailed discussion and citations on both sides of the debate, see Metzger’s Textual Commentary on the Greek New Testament.) The United Bible Societies’ editorial committee selected “God” as the main reading for this reason, labeling this change a “C.” (The letters A through D were used to indicate the relative degree of certainty of their choices, the letter “A” being the most certain and “D” being the least.)
As for the second variant, the textual evidence here is more lopsided and clearly shows that reading 2 is secondary, supported mostly by the Byzantine witnesses that had conflated the earlier variant. But even if we choose reading one (as the UBS did, labeling this one a “B”), we are still left with the grammatical ambiguity of what it means. Either translation is possible. It is, however, unidiomatic if the intended meaning were “his own blood”; the more usual way of expressing this would be either dia tou heautou haimatos or dia tou haimatos tou heautou, or perhaps an instrumental dative in lieu of dia + genitive. The other reading is also a bit awkward; first, for having a second genitive phrase dependent on one to which it happens to agree in case, number and gender, and second, for lack of a clear antecedent to idiou. The first bit of awkwardness is what it is (such constructions certainly occur elsewhere in the New Testament); the second can be solved in one of two ways:
– Some have suggested that the word huiou “son” originally stood at the end of the text and dropped out. While this would be easy enough given the repetition of the –ou genitive ending, this is a minority view and really unnecessary.
– Others (more persuasively, in my view) argue that the word idios (its nominative form) had a distinct usage in early Christianity, similar to agapetos “beloved” or monogenes “only.” In favor of this understanding, according to Moulton, this usage is attested in Greek papyri, as in a letter beginning “[So-and-so] to his own [friend], greeting.” Therefore, you will sometimes see the word “Own” capitalized by itself, and you will sometimes see the word “son” added (either with or without brackets). That is, either “the church of God, which he purchased with the blood of his Own” or “with the blood of his own [son].”
I personally like this last solution. It seems likely to me that when this usage died out, the text began to be read as referring to God’s own blood, and so the word “God” was changed to “Lord” to ease the difficulty that reading caused. Therefore, I would understand the verse to be saying that the church belongs to God, because he has purchased or obtained it with the blood of his own son.
My impression based on the commentaries I have seen is that over time this reading has become something of a dominant view. A good illustration of this is the RSV. The first edition read “the church of the Lord which he obtained with his own blood,” with footnotes saying “Other ancient authorities read of God” and “Or with the blood of his Own.” But the second edition and the NRSV switch the text and notes around; both read “with the blood of his own Son.” The NRSV footnotes say “Or: with his own blood; Gk with the blood of his Own.” I believe the progression of readings from the RSV to the NRSV moves in the correct direction.