What is the Spirit’s role in justification—the justification of Jesus and of sinners?
In Protestant theology, the Spirit is typically on the “subjective” side of justification. By awakening faith, the Spirit enables sinners to receive the justifying verdict of the Father who imputes the righteousness of the Son to the ungodly.
But 1 Timothy 3:16 suggests a different role for the Spirit. Paul says that Jesus was “justified in the Spirit,” a reference to the resurrection. The Spirit's role in justification is not to awaken a subjective disposition in Jesus. In 1 Timothy, the Spirit is the agent to accomplish justification, and He accomplishes that by being the agent of the resurrection of Jesus.
Paul elsewhere highlights the Spirit's role in the resurrection of Jesus. In Romans 1:1–4, Jesus is declared Son of God with power by the resurrection according to the Spirit of holiness. That links the work of the Spirit to the resurrection. Romans 8:11 speaks of the Spirit who raised Jesus from the dead, and this One gives life through the Spirit who indwells. If we are raised through the Spirit, then it seems that the Spirit is also the one who raised Jesus.
The Spirit is the enlivening breath of the Father. As the Father formed the world through the hovering Spirit, so the Father forms a new Adam and a new world by sending the Spirit to raise the incarnate Son. If the Father raises Jesus by the Spirit, and the resurrection is also Jesus’ justification, then the Spirit is the one by whom the Father justifies Jesus, by whom the Father reverses both the verdict of guilt and the sentence of death.
It may seem odd to attribute this sort of judicial/legal activity to the Spirit. The Spirit seems to be on the “participation” side of biblical theology, rather than the “forensic” side. But the New Testament regularly describes the Spirit’s work in forensic terms. The Spirit is paraklete, the advocate for the defense, the one who comes alongside to secure our acquittal, the one who justifies by being our advocate (John 14:16). The Spirit bears witness, a legal concept (Acts 5:32). The Spirit convicts the world of sin, righteousness, and judgment (John 16:8). In keeping with this portrait of the Spirit’s work, the Spirit performs a forensic act when He justifies the Son.
The Spirit’s role is not merely on the subjective side of justification. Justification happens in the resurrection of Jesus, when the Spirit takes the side of the crucified to vindicate Him in resurrection. Justification happens in the life of an individual when the Paraklete comes alongside to be our advocate against the enemies of Sin and Death, justifying us by bringing us to new life. The Spirit doesn't merely allow us to receive what is otherwise accomplished. He accomplishes justification.