John Piper:

God does not justify us in the past, or save us in the future, except through Jesus Christ his Son. O how we should meditate on the work of Christ. Because here we meet the work of God. If you want to know the love of God, know the work of Christ.

Where do we see this? It is made explicit in both verse 9 and verse 10. Verse 9: “Much more then, having now been justified [that God’s work] by His blood [that’s Christ’s work in dying], we shall be saved from the wrath of God [that God’s work] through Him [that’s the work of his Son, Jesus Christ].” The Son bought our justification in the past when he died for us, and he mediates our salvation in the future because he lives for us. God saved in the past through Christ. He will save in the future through Christ.

It’s even more clear in verse 10: “For if while we were enemies we were reconciled to God [that’s God’s work] through the death of His Son [that’s the work of his Son in dying for us], much more, having been reconciled, we shall be saved [that’s God’s work] by His life [that’s Christ’s work].”

So the third observation is this: Both God’s past work and God’s future work to rescue us are through the work of Christ his Son. Justification and reconciliation in the past and salvation in the future are through Jesus Christ. He is indispensable in the work of salvation. And the Father means for him to have his glory.