A couple days ago I was reading Ephesians 1 in Greek during my morning Bible-reading time. As I read, I was drawn to two phrases that are clearly present in Greek but are often eliminated in English. The two expressions that get removed are “into him” (εἰς αὐτόν) in the middle of verse 5 and (“in him”) (ἐν αὐτῷ) at the end of verse 10. Presumably these expressions get cut because they are deemed unnecessarily repetitive.
ESV translates verse 5 as “he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will,” and NIV translates it as “he predestined us for adoption to sonship through Jesus Christ, in accordance with his pleasure and will.” You can’t see it in English; but in Greek there is an “into him” right after “Jesus Christ.” Both translations leave it out.
Something similar happens at the very end of verse 10; the words “in him” are normally removed when rendered in English. Ostensibly, the reason for the removal is that “in Christ” has been employed earlier in the verse, and “in whom” appears right at the beginning of verse 11. One example of the removal of this phrase is the NET Bible, which, like many other translations, leaves out “in him.” Here is the verse with the “in him” included in brackets where it appears in Greek: “to head up all things in Christ – the things in heaven and the things on earth [in him]. In Christ we too have been claimed as God's own possession…”
I have great sympathy for translators who seek to produce smooth English renderings. Meaning can be lost if a translation is too wooden. But here’s the rub: Union with Christ (“in-Christ-ness”) is crucial to Paul’s thought and is repeatedly snuck in by Paul when he writes about many different topics. Con Campbell uses the metaphor of a web to describe how important this concept is in the writings of Paul. Union with Christ can be viewed as a web that extends into the rest of Paul’s theology and helps to hold it together.
If this is true, then perhaps Paul isn’t simply being redundant. It could be that he is being intentionally repetitive – even in-your-face repetitive – because the idea of being united with Christ is so significant to him. Besides, who says that such a compositional move was stylistically satisfying to Paul’s first readers as they read Paul’s letter in Greek? Paul was purposely – repeatedly, redundantly, and regularly – repetitive, just as I was in this sentence. He wanted to press upon us the idea that everything that matters is “in Christ.” Hmmm … I wonder how much we lose when we translate out such expressions for the sake of smoothness in English?
 Constantine R. Campbell, Paul and Union with Christ: An Exegetical and Theological Study (Grand Rapids, MI: Zondervan, 2012), 437.