If I could think of any doctrine that would sum up the Christian experience, for me, at least, it is union with Christ. As I look at the key texts on justification, regeneration, sanctification, glorification, it seems to me that every one of these benefits stems from union with Christ.
Paul says that “all the treasures of wisdom and knowledge are hidden in him” (Col 2:3), and that God has blessed believers “in Christ with every spiritual blessing in the heavenly places” (Eph 1:3). Paul then goes on for the rest of his eloquent run-on sentence in Ephesians 1 by saying that in Christ, God has given us holiness (v. 4), blamelessness (v. 4), adoption (5), redemption and forgiveness of our trespasses (v. 7), and the inheritance of the Spirit (v. 13-14). All of these are ours by virtue of being in Christ. As Martin Luther says, “all his is mine and all mine is his” (you can fine the full quote in my previous post here).
More than this though, Paul says that not only is Christ’s righteousness mine, and my sin his, but by virtue of being in him, even his present reign at the right hand of the Father is mine. He says, “so if you have been raised with the Messiah, seek what is above, where the Messiah is, seated at the right hand of God…For you have died (your old self), and your life is hidden with the Messiah in God” (Col 3:1-2). So because I am in Christ, I am seated in him at the right hand of the Father. Paul becomes even more ecstatic in describing the union we have in Christ by saying that “everything is yours, and you belong to Christ, and Christ belongs to God” (1 Cor 3:22-23). In other words, not only do we reign in Christ, but the entire universe belongs to us be virtue of our union with him.
For Paul, the doctrine of being in Christ is central to the Christian experience. It is so central that all things are found in him, and nothing of value can be found outside of him. Perhaps Paul’s most encompassing statement is found in 1 Corinthians 1:30, where he says that Christ “became God-given wisdom for us — our righteousness, sanctification, and redemption, in order that, as it is written: The one who boasts must boast in the Lord”. It’s all there. The entire Christian life is in Jesus!
As Luther once said, that by union with Christ, every Christian is “so exalted above all things that…he is lord of all things without exception, so that nothing can do him any harm”.