Paul continues to explain the privileges of living in the Spirit.  In light of God’s power available to us we are under obligation to live according to the Spirit.  Being under obligation shows that we have a role in our sanctification but we also know we’re never without the Spirit’s leading and our Father’s presence every step of the way.  We have a responsibility to live and suffer as God’s children, but as His children we’ll never be alone and we know our Father wants us to succeed in becoming more like Him and to ultimately be in His presence in glory.   

12-13
In verse 11 Paul said that God’s power that raised Jesus from the dead (a resurrection that defeated death completely since Jesus lives for all eternity) is available to us to battle sin and live for Him even in bodies enslaved to sin (an absolutely amazing promise – an eternal, sovereign, omniscient and omnipotent power INDWELLS us).  Since that’s true, we’re now under obligation to the Spirit (the Spirit of Him who raised Jesus from the dead) to live according to the Spirit.  The Spirit indwells us and empowers us, so we have an obligation to live as the Spirit leads.

Now you might be thinking, “Uh…my Bible doesn’t say that in verse 12.”  You’re absolutely right, it doesn’t.  But though you can’t see it, it’s implied in what Paul says.  He assumes his readers know that if we aren’t obligated to the flesh to live according to the flesh (what he DOES say), it means we ARE obligated to the Spirit to live according to the Spirit.

It’s interesting that he says we’re under obligation, isn’t it?  What does that imply?  It implies that we don’t just sit back and let the Spirit take care of us.  We have a role in our sanctification.  He essentially says this in verse 13 as he continues his thought.  If we live according to the flesh (meaning that we live only for this world without a thought for God or His Law or His work of redemption) we must die (because if we have no thought for God we aren’t His – and according to verses 6-8 above we’re hostile toward God and cannot please Him).  BUT, if by the Spirit we are putting to death the deeds of the body, we will live.  In both cases the human is the actor, right?  Man lives according to the flesh or man puts to death the deeds of the body by the Spirit.  Regardless of how man lives, he has responsibility.

He doesn’t, however, have responsibility alone.  Paul doesn’t say that it’s all on man to make his sanctification work.  The Spirit empowers too.  How do we put to death the deeds of the body?  By the Spirit.  Remember that this whole chapter is a treatise on life in the Spirit and he just said in verse 11 that the incredible power of God is available to us through His Spirit.  So while we have responsibility, we don’t act alone or in our own strength.  We’re responsible, but we’re not solely (souly?) responsible.  We don’t get to wash our hands of our growth and say, “If I’m not growing it’s because God hasn’t grown me,” but we also don’t have to get up every day and think, “It’s all on me to live righteously today.”  God didn’t save us by grace only to leave us alone to become more like Him.

So if we ask, “Who’s responsible for our sanctification, God or us?”  The correct answer is, “Yes.”  It’s both/and – not either/or.  We both have responsibility.  It’s ultimately up to me how I live (according to the flesh or according to the Spirit) but I never live alone if I live according to the Spirit and I’d never truly live according to the Spirit if I tried it alone.

Before we move on to verse 14, notice the verb tenses in this section.  They’re all present, right?  That means we live according to the Spirit and put to death the deeds of the body on an ongoing basis.  This isn’t a one-and-done situation.  We continually live according to the Spirt and we continually put to death the deeds of the body by the Spirit.  Remember that what we studied in 7:14-25 was all in the present tense.  The fight that we wage against our body of sin never ends this side of eternity.  We live in God’s power available to us and in light of what He’s done for us and we never stop living that way as long as we’re on this version of earth.  We continually fight and we continually choose and we never stop fighting and choosing.  What’s amazingly reassuring, however, is that we fight this ongoing fight always in the strength of the Spirit.  If the fight never ends, the Spirit’s presence and power and leading never end either.  No matter how long it takes, we never fight alone.

14-17
We live by the Spirit and we’re also led by the Spirit.  The Spirit’s power demonstrated in our lives and His leading of us show that we’re His.  God reassures us by acting through us.  As we put to death the deeds of the body by the Spirit we’re repeatedly assured that we’re His sons.  Ultimately, our Father’s Spirit leads us as His sons.  [Progress in sanctification gives assurance of salvation just as good fruit proves good trees – Matt 7:16-20.  No progress, no assurance – II Pet 1:1-11.]

Why?  Because we’ve received a spirit (or Spirit) of adoption into the family of God.  When we served sin we lived under a spirit of slavery and fear.  But now that we’re in the Spirit we’re no longer slaves but adopted sons.  We don’t have a taskmaster, we have a Father.  And that Father is there for us and wants us to live intimately with Him (Abba! Father! – denotes familiarity and intimacy).

This is a third element to our sanctification.  We have a responsibility to live according to the Spirit and put to death the deeds of the body.  We do those things through the power of the Spirit.  The Spirit indwells us and enables us.  On top of those two truths, however, we also know that the Spirit who indwells us belongs to our FATHER.  And if it’s our Father who enables us it makes sense that He wants us to succeed.  We don’t serve a judge waiting to whack us when we’re out of line.  We serve a Father who longs for us to grow in the grace and knowledge of Him and of His redemption (Deut 5:29, Jn 15:8).

Paul says again in verse 16 that the Spirit of God reassures us.  He bears witness with (or ‘to’) our spirit that we belong to Him.  It’s the Spirit’s work in us that shows us we’re His.  The Spirit will bear fruit (Gal 5:22-23) and that fruit will bear witness to us and to others that we’re a child of God.

If we’re children of God, then we’re heirs also.  By this, Paul doesn’t mean heirs in the traditional sense of inheriting something when our father dies.  He means that we’re heirs of the promises of God.  Jesus promised eternal life and a place in His presence (“I go to prepare a place for you…that where I am there you may be also” Jn 14:1-3).  It’s as God’s children that we know those promises are true for us.  Even more, we’re fellow heirs with Christ.  We aren’t equal to Jesus but we’re equally heirs.  Remember what Paul has said in these chapters about our status in Christ.  We died with Him (6:3-4), we rose with Him (6:4), we live with Him (6:8), we’re free from condemnation because we’re in Him (8:1).  And since we’re in Him we’re fellow heirs of the promises of God with Him.  We’ll be in God’s presence for all eternity just as He will be.

At the end of verse 17, Paul adds another layer to our identification with Christ: if we’re in Christ we suffer with Him.  This seems a little out of the blue since Paul hasn’t said anything about suffering so far in this chapter, but it goes along with our status as Christ’s fellow heir and also gives us another means of knowing that we’re His.  Suffering equals assurance.  Jesus told His disciples that they would suffer because He suffered (Matt 10:16-33; Jn 16:33).  Since that’s the case, our suffering is more evidence that we belong to Him.  Suffering proves adoption (which is why Paul states it as an ‘if’ clause – if we don’t suffer we have less evidence of membership in a family known for suffering).  And if we’re adopted, then as fellow heirs we’ll be glorified with Christ (I Jn 3:1-2).

Thoughts
So we can start to add this all up.  We’re in Christ.  We live according to His Spirit with His Spirit indwelling us and leading us.  We’re responsible for living according to the Spirit and for putting to death the deeds of the body but we do it by the Spirit’s strength and according to His leading.  We have a role in our sanctification but we’re never alone in pursuing it.  Even more, the Spirit who leads and indwells us is the Spirit of our Father.  We’re adopted sons, not fearful slaves.  We have a Father who loves us and wants us to succeed in becoming more like Him.  And as we become more like Him we’ll become more assured that we’re His.  His Spirit’s work in our lives will continually prove that we belong to His family.  Belonging to the family entails suffering but suffering with Christ ultimately results in glory with Him.  So we’re His, He’s our Father, He enables us to become more like Him, and we’ll someday be with Him in glory for all eternity.

There is therefore now no condemnation for those who are in Christ Jesus.
Bu if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit who indwells you.
The Spirit Himself bears witness with our spirit that we are children of God, and if children, heirs also, heirs of God and fellow heirs with Christ, if indeed we suffer with Him in order that we may also be glorified with Him.