Introduction
The Bible teaches us that in one sense, God is one. Deuteronomy 6:5 plainly declares, “The LORD our God, the LORD is one.” God is one in his divine essence. Yet the Bible also teaches that, in a different sense, God is three. That within the one divine essence of God, there are three persons who have always existed together – God the Father, God the Son, and God the Spirit. This is why, when Jesus gave the Great Commission to His disciples in Matthew 28, he said, “Go therefore and make disciples of all nations, baptizing them in the name” – just one name, one reputation, one essence – “in the name of the Father and of the Son and of the Holy Spirit.” There’s one name – one divine nature. But that name belongs to three distinct persons.

So far in Romans 8, we’ve seen that those who turn from their ungodly deeds and who turn to Christ for forgiveness and cleansing – these people have new life in the Spirit of God.
Throughout Scripture, there are many words and phrases used to describe the Spirit. The Spirit is referred to as the Holy Spirit – meaning that the Spirit himself is the Spirit of ultimate sacredness and purity. He’s called the Spirit of God and the Spirit of Christ because He’s the divine Spirit who proceeds from the Father and from Jesus Christ (the Son) in order to apply the benefits of God’s salvation to God’s people.

Here in our text, you’ll see that the Spirit is given another title. In verse 15, he’s called the Spirit of Adoption. In fact, our text tonight focuses on the topic of adoption – especially how the Spirit of Adoption works in the life of a Christian. So in our time together, I want to point out 4 ways that the Spirit of Adoption works in God’s people.
New Direction
First, the Spirit of adoption gives new direction – He gives new direction to guide us in life.
Verse 14 tells us “All who are led by the Spirit of God are sons of God.”
Verse 14 is saying that following the Spirit and Sonship – these two things go together. You’ll know who the sons of God are, because the sons of God will follow the Spirit of their Father. A Son will respect his father’s status, follow in His father’s wisdom, and trust in His father’s love.

But not everyone is a child of God. In fact, every human being is naturally separated from God – an enemy of God – fallen and corrupt, enslaved to sin. Those who are enslaved to sin will find themselves seeking self-advancement, self-indulgence, and self-justification over and over again – and you can be certain that a life that focuses on self is a life that’s far from God.

This is why I say the Spirit gives new direction – because the Spirit exposes how human-centered our life is, and teaches us to center our life on God.
Notice, we don’t just need this new direction for our behavior. Our behavior does change – but this is because you and I ultimately have a new direction for our hearts. If the Spirit is leading you, that means that you’re not trying to lead yourself. It means that your heart has been humbled before God. You’re letting Him call the shots. You’re submitting to the authority of His Word and Spirit.

When you’re led by the Spirit, you’ll spend less time amusing yourself and more time adoring God and assisting your neighbor. When you’re led by the Spirit, you’ll spend less time in front of the bathroom mirror to see the condition of your face, and you’ll spend more time in front of your Bible, which acts as a mirror to show you the condition of your soul.

When you’re led by the Spirit, you’ll spend less time trying to draw attention to yourself and more time pointing people to wisdom and power of God. When you’re led by the Spirit you’ll structure your calendar differently, you’ll organize your budget differently, you’ll care for the people around you differently – you’ll view God differently – Why? Because the Spirit of Adoption is now the primary force that leads your heart – and He teaches you to live in light of your new identity.
New Identity
This leads to my second point – the Spirit of Adoption confirms our new identity. “For all who are led by the Spirit of God are sons of God.” Verse 15 likewise affirms that we’ve received the Spirit of adoption as sons, by whom we cry “Abba, Father.” If anyone is in Christ, that person has a new identity as a son of God. But what does it actually mean to be sons of God?

Don’t get distracted when the text says sons rather than “sons and daughters.” Whenever the Greek language uses the plural sons, it can include both men and women – both sons and daughters.

Instead, pay attention here to the key contrast made between being a son and being a slave. Verse 15 says, “…you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry ‘Abba, Father.’”

We used to be slaves – enslaved, not to God, but slaves to ungodliness. A slave is someone with no rights, no enduring relationship with the Master of the House, no future prospects. And as a result, the slave lives in fear – fear that the Master will be displeased, fear that the Master will be too demanding, fear that the Master will send him away.

But everyone who trusts in Christ receives His Spirit – not a spirit of slavery – not a Spirit of uncertainty and separation – not a Spirit for falling back into fear – but a Spirit that confirms your new identity. You are God’s sons – his children.

A son has full rights and benefits in the home, a stable relationship with the Father of the House, and a bright future. An adopted son fears nothing, because He knows his relationship with His Father has been certified – the courts of heaven have reached a final verdict! – his place in the family of God is certain.
New Comfort
With this new identity as a child of God, we have new comfort. And this is a third way the Spirit of Adoption works – he brings new comfort.
The Spirit affirms that the Almighty, transcendent God, who created angels, stars, canyons, and waterfalls – who is eternally satisfied and complete without us – he paid the cost to adopt you. He brought you into his family – not because he felt lost without you, but because he knew you’d be lost forever without him. God himself has eternally pledged himself to be your Father – you are his, and he is yours.

And Jesus reminds us in Matthew 7:11, “If you, then, who are evil, know how to give good gifts to your children, how much more will your Father who is in heaven give good things to those who ask him.” You can be comforted in knowing – your Father knows what’s best for you. He’ll protect. He’ll provide. All of his children are secure. Earthly fathers may fail, but God will remain faithful.

Verse 15 reminds us that the Spirit of Adoption isn’t a Spirit of fear. Instead, the Spirit comforts our anxious hearts. He teaches us to call out to God confidently and intimately.
When we say God is our Father, it doesn’t just mean that he’s some sort of distant, cosmic creator of all. No, He’s personally our Father who brings us up into His embrace. He gives each of us a place at the family table. He tells you and me, I love you, in a way that he doesn’t speak to the rest of the world. The Spirit of Adoption testifies with our Spirit, that we are, in fact, children of God ¬¬– not house guests, not foster kids, not exchange students – but His own, dearly beloved children.

Your Father won’t forget you. So don’t forget who you have as your Father! Sometimes when we get busy, or we get overwhelmed with sudden changes – we forget who we are. We become anxious, angry, depressed people because we live like orphans – as though everything rests on us. But all the while, we forget that we’re princes and princesses of an everlasting kingdom – children of an Almighty King.
Don’t lose track of who you are. But let the Spirit of Adoption comfort you, reminding you that you are children of God…
New Inheritance
And (verse 17!) if children – then [also] heirs – heirs of God and fellow heirs with Christ. This is the fourth way the Spirit of Adoption works – he testifies, not only that we’re children, but we’re also heirs – that we have a new inheritance.

I say this is a new inheritance because it’s very much different from what we’d naturally have coming to us. As I mentioned earlier – we were once slaves – slaves to sin. We inherited our inner corruptions and sin from our parents, they did from their parents, and so on and so forth, all the way back to Adam and Eve. The only inheritance that slaves can pass on to their children is their slavery – so that’s all we would have – slavery to sin, fear of judgment, imminent death – that’s all we’d have without Jesus.

But notice that verse 17 points out that we’ve been made heirs of God and co-heirs with Christ. Christ has qualified us to receive this new inheritance. He is rightly the heir of all things, the perfect Son of Man and Son of God – Colossians 1:16 says that all things were made through him and FOR HIM. All things are for Jesus.

Yet Jesus doesn’t keep it all for himself. Here’s the astonishing thing about Jesus. He gave up his own life – he gave himself up to humiliation and death on the cross – why? So that he could further give us a portion of His birthright. He didn’t insist on keeping his property, his dignity, his health – even his own life. But he laid all these things down so that we could be raised up to share in his inheritance. Not a flimsy, falling apart inheritance – but one that’s imperishable, undefiled, and unfading.

The Bible indicates that this inheritance includes a new heavens and earth – a new city without darkness, without death, without pain, without tears – but the best thing about our inheritance will be having God himself – beholding his glory, drinking forever from the wells of his goodness, exploring the boundless reaches of his grace.

You’ll notice, though, in verse 17: before the glory of the new inheritance comes suffering. Jesus Christ, the Son of God, walked along a road of humiliation before entering into paradise. So we shouldn’t be surprised when we have the same path. The difficulties you face in life don’t nullify God’s Fatherly care, or the legitimacy your adoption. Rather, whenever you suffer you should be encouraged to know – you are simply following in the footsteps of Christ. If you share in his suffering, you will also share in his glory, as a true child of God.