You, however, are not in the realm of the flesh but are in the realm of the Spirit, if indeed the Spirit of God lives in you. And if anyone does not have the Spirit of Christ, they do not belong to Christ. But if Christ is in you, then even though your body is subject to death because of sin, the Spirit gives life because of righteousness. And if the Spirit of him who raised Jesus from the dead is living in you, he who raised Christ from the dead will also give life to your mortal bodies because of his Spirit who lives in you.
Romans 8:9-11 NIV
This is an interesting passage that stresses the importance of the indwelling Holy Spirit. Paul generally refers to the Holy Spirit as the Spirit or the Spirit of God. But here, in addition to both of those terms, he also uses the Spirit of Christ. To make it even more interesting, in addition to the Holy Spirit living in us, he refers to Christ being in us.
No passage in the Scripture explicitly provides us with the definition of the Trinity that came out of the Nicene council. But this passage is one that clearly would point to it. It seems that in Paul’s mind, the Holy Spirit could be considered the Spirit of God (the Father) or the Spirit of Christ (the Son). They were the same.
But how could this be unless God the Father and God the Son are not in some way a single being? This is affirmed in the Gospel of John, where John claims that the Word (Jesus) was God (John 1:1). And Jesus claims to be one with the Father (John 10:30).
Paul’s reference in this passage to Christ being in us overlaps with the Holy Spirit being in us. Are they both in us? Or are they so closely connected in Paul’s mind that if one of them is in us, both are?
Does this passage from Paul prove the Nicene formulation of the Trinity, a God having one essence with three persons? No, it does not. But I believe it does provide powerful support for this doctrine. A doctrine that is central to our understanding of the nature of God.
