You don't have to defend yourself | Romans 8:16
The Spirit himself bears witness with our spirit that we are children of God. Romans 8:16
A witness is someone who speaks about what they have seen. Here we are told that one of the main assignments of the Spirit in our lives is to bear witness with our spirit that we are indeed God's children.
I don't need to spend very long explaining to you why this assignment is essential. There are so many reasons to doubt whether or not God considers us his children. We sin. We forget about him. We pursue other things. We get it wrong, more often than not. We need to be assured and reassured that God still considers us his children, in spite of the fact we ourselves often live as though he were not our Father.
A witness speaks on the basis of evidence they have seen. Obviously the Spirit's evidence to you that you are God's child is not solely based on your performance. The reason we need his witness, after all, is that too often we give evidence in the other direction. We live as though we were not God's children. And that's why we sense impending condemnation. But remember, there is no condemnation. And that's an unbelieveable fact.
That is why we need the witness, the evidence, the testimony, of the Spirit, to tell us what else he has seen, beyond just our prodigal actions and attitudes.
The Spirit, who is God himself, has witnessed the following events, and on the basis of these events, he can testify that we are God's children:
The Spirit was there when God created and chose us. The Spirit can testify to the fact that God has created us to be his children since before the world was made. He was there when that decision was made, and he has been hovering over our lives, waiting for the word of God to fall on our ears at the moment he has decided to give us life.
...he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love he predestined us for adoption to himself as sons through Jesus Christ, according to the purpose of his will... Ephesians 1:9-10
He was there when God saved us. The Spirit also was there in that intimate moment when he gave birth to our spirits. Like a midwife, he watched us pass from death to life when we believed the gospel. He was the witness of that first spark of awareness when we latched onto the word of God as our hope and he saw our living faith before we ever uttered our first words of faith.
That which is born of the flesh is flesh, and that which is born of the Spirit is spirit...It is the Spirit who gives life; the flesh is no help at all. John 3:6; 6:63
He is there when we suffer the power of sin. The Spirit who dwells in our hearts knows all our thoughts and all our struggles. He doesn't simply see us falling into sin, he is there for the whole agonizing battle that took place before it. This, I think, is why he has so much compassion for us even in our sin. He knows how sin preys on us and he hates it. He can testify that we hate our sin, even though our record would indicate otherwise. And that's why he changes us and empowers us.
If you love me, you will keep my commandments. And I will ask the Father, and he will give you another Helper, to be with you forever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you. John 14:15-17
He is there all throughout the process of making us holy. We tend to measure our success against sin by progress. And that's one way to measure it - a good and accurate way. But our measuring tools are pretty crude. We are only able to measure progress with a yardstick and maybe a magnifying glass. The Spirit's measuring instruments, however, are finely calibrated, microscopic tools able to see progress at a deeply spiritual level. Just as in the womb he was there, seeing every cell and fiber knit together (Ps 139:13), so now he is in our spirits, seeing every event of our lives and every thought of our hearts and he sees that all is being worked together for our ultimate development into the image of Christ (Rom 8:28-29). He can testify that, although you may feel like nothing's happening, nothing's changing, you are indeed being knit together spiritually into exactly the person God wants you to become - pleasing to him.
Now the Lord is the Spirit, and where the Spirit of the Lord is, there is freedom. And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit. 2 Corinthians 3:17-18
He was there when Christ took his throne. The point is, he saw sin beaten down as Christ was raised from the dead. He saw a man - a son of Adam - take the throne to rule over heaven and earth, the inheritance that was promised to man by God (Ps 8:5-6). The Spirit knows what that means. It means that God has triumphed in his efforts to redeem and restore mankind. Including you. The Spirit saw a man on the throne; he was sent by the King to tell you that humanity is restored to God in Christ. He knows that his work in your life will succeed. And he's here to make sure it does.
“But when the Helper comes, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father, he will bear witness about me. John 15:26
We can trust the Spirit's witness. He knows what he's talking about.
And the Spirit is the one who testifies, because the Spirit is the truth...Whoever believes in the Son of God has the testimony in himself... And this is the testimony, that God gave us eternal life, and this life is in his Son. 1 John 5:6, 10-11
Claim it. When your inner voice is on a condemnation rampage, try telling it to be quiet and listen to the Spirit. Put him on the stand and let him speak. When your self-condemning heart asks, "Well who is he anyway?" tell yourself, "He's God." And then listen.