Of the many things that God does for his people when they come to him in faith—all of them astonishing—perhaps the most astonishing is that he unites us with his Son.
Now, all of God’s people are his sons and daughters, members of his family (Ep 1.5). But Jesus Christ is his Son in a way that no other person is; he is the Son (Mt 28.18-20), the one-of-a-kind, unique Son (Jn 3.16), the only Son in that sense—God the Son, in whom the Father is well pleased (Mk 1.11).
And we are united with that Son, placed in him; we are the body of which he is the Head (Ep 1.22-23).
It seems that Paul is simply overwhelmed with this truth. He uses the expression “in Christ” 74 times in his 13 epistles; “in Jesus” 6 more times; “in the Lord” 43 more times; and “in him” (with reference to the Son) 17 more times. That’s 140 times in total. He just can’t seem to get the concept out of his mind.
And Paul isn’t the only New Testament writer to address the concept in depth. John certainly does, and Peter alludes to it as well.
Strangely, it’s not something that the modern church seems to prioritize. You find a few cases along the way—Sinclair Ferguson’s video series on the topic is noteworthy—but across conservative evangelicalism it doesn’t generally seem to get the attention it deserves.
So I think I’ll write a series of posts on the topic. It won’t have the depth of book-length theological treatments, of course, but I’d like to survey the basic biblical data in outline form.
To begin with, I suppose the clearest statement of the basic principle comes from John, at the end of his first epistle. He writes,
19 We know that we are of God, and that the whole world lies in the power of the evil one. 20 And we know that the Son of God has come, and has given us understanding so that we may know Him who is true; and we are in Him who is true, in His Son Jesus Christ. This is the true God and eternal life (1J 5.19-20).
Here, interestingly, John says that we’re in both the Father (“Him who is true”) and “in His Son Jesus Christ.” This is one of the last portions of the Scripture to be written, and John is likely encapsulating all that the New Testament writers have written before. I think we can consider this the climax of biblical teaching about the relationship between God and his people: we are in him, united with him, one with him, the very God of heaven. And that union with God is made possible by our union with the Son, who is united with us as a perfect, unfallen human being—one with us, as it turns out, forever.
This is an astonishing concept.
This is something that Christ himself predicted. In his farewell address to his eleven disciples, he said,
18 “I will not leave you as orphans; I will come to you. 19 After a little while the world will no longer see Me, but you will see Me; because I live, you will live also. 20 In that day you will know that I am in My Father, and you in Me, and I in you (Jn 14.18-20).
“That day,” I would suggest, is the last day, the eschaton, the resurrection, when we shall know even as we are known (1Co 13.12), when we shall be perfectly united with the Father through the Son. But there is much in the New Testament to indicate that that union is occurring now, even before the death of death and the eradication of sin. More on that later in the series.
Jesus not only predicted this union; he prayed actively for it. In the longest recorded conversation between members of the Godhead, Jesus prayed,
20 “I do not ask on behalf of these alone, but for those also who believe in Me through their word; 21 that they may all be one; even as You, Father, are in Me and I in You, that they also may be in Us, so that the world may believe that You sent Me (Jn 17.20-21).
And the Father, ever at one will with the Son, has answered that prayer (1Co 1.30).
This has always been the plan.
We’ll look into the details in the coming posts.