Romans 8:16

The Spirit itself testifies with our spirit, that we are children of God:

2 Corinthians 1:22

Who also having sealed us, and given the pledge of the Spirit in our hearts.

2 Corinthians 5:5

And he having brought us about to this same, God, he having also given us the pledge of the Spirit.

Ephesians 1:13

In whom ye also, having heard the word of truth, the good news of your salvation: in whom also having believed, ye were sealed by the holy Spirit of solemn promise,

2 Corinthians 1:12

For our boasting is this, the testimony of our consciousness, that in simplicity and purity of God, not in fleshly wisdom, but in the grace of God, we turned back in the world, and more eminently to you.

Ephesians 4:30

And grieve ye not the Holy Spirit of God in which ye were sealed to the day of redemption.

1 John 3:19-22

And in this we know that we are of the truth, and we will yield our hearts before him.

1 John 4:13

In this we know that we remain in him, and he in us, for he has given us of his Spirit.

1 John 5:10

He believing in the Son of God has the testimony in himself: he not believing God has made him a liar; for he has not believed the testimony which God has testified of his Son.

Romans 8:23

And not only, but also they having the first fruits of the Spirit, and we ourselves groan in ourselves, waiting for the adoption as a son, the redemption of our body.

Romans 8:26

And likewise also the Spirit takes hold together, and assists our weaknesses: for what we would pray for as we ought, we know not, but the Spirit itself intercedes for us with inexpressible groanings.

Treasury of Scripture Knowledge

Summary

The Spirit itself beareth witness with our spirit, that we are the children of God:

General references

Bible References

Spirit

Romans 8:23
And not only, but also they having the first fruits of the Spirit, and we ourselves groan in ourselves, waiting for the adoption as a son, the redemption of our body.
2 Corinthians 1:22
Who also having sealed us, and given the pledge of the Spirit in our hearts.
2 Corinthians 5:5
And he having brought us about to this same, God, he having also given us the pledge of the Spirit.
Ephesians 1:13
In whom ye also, having heard the word of truth, the good news of your salvation: in whom also having believed, ye were sealed by the holy Spirit of solemn promise,
Ephesians 4:30
And grieve ye not the Holy Spirit of God in which ye were sealed to the day of redemption.
1 John 4:13
In this we know that we remain in him, and he in us, for he has given us of his Spirit.

With our

2 Corinthians 1:12
For our boasting is this, the testimony of our consciousness, that in simplicity and purity of God, not in fleshly wisdom, but in the grace of God, we turned back in the world, and more eminently to you.
1 John 3:19
And in this we know that we are of the truth, and we will yield our hearts before him.
1 John 5:10
He believing in the Son of God has the testimony in himself: he not believing God has made him a liar; for he has not believed the testimony which God has testified of his Son.

General references

Galatians 3:26
For we are all sons of God through faith in Christ Jesus.