Romans 8:16

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

2 Corinthians 1:22

he who also sealed us, and gave the Spirit as a pledge in our hearts.

2 Corinthians 5:5

Now he that hath prepared us for this very thing is God; who also gave to us the Spirit as the pledge.

Ephesians 1:13

in whom ye also, after having heard the word of truth, the glad tidings of your salvation, in whom, I say, having also believed, ye were sealed with the Holy Spirit that was promised,

2 Corinthians 1:12

For our glorying is this, the testimony of our conscience, that in simplicity and the sincerity which is of God, not in fleshly wisdom, but in the grace of God, we have conducted ourselves in the world, and especially toward you.

Ephesians 4:30

and grieve not the Holy Spirit of God, whereby ye were sealed unto the day of redemption.

1 John 3:19-22

And hereby we know that we are of the truth, and shall assure our hearts before him;

1 John 4:13

Hereby we know that we dwell in him, and he in us, because he hath given us of his Spirit.

1 John 5:10

He that believeth in the Son of God hath the witness within him; he that believeth not God hath made him a liar, because he hath not believed in the witness which God hath borne concerning his Son.

Romans 8:23

and not only so, but even we ourselves also, though having the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption as sons, for the redemption of our body.

Romans 8:26

In like manner the Spirit also helpeth our weakness; for we know not what to pray for as we ought, but the Spirit itself intercedeth with groans which cannot be expressed in words.

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 so, but even we ourselves also, though having the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption as sons, for the redemption of our body.
2 Corinthians 1:22
he who also sealed us, and gave the Spirit as a pledge in our hearts.
2 Corinthians 5:5
Now he that hath prepared us for this very thing is God; who also gave to us the Spirit as the pledge.
Ephesians 1:13
in whom ye also, after having heard the word of truth, the glad tidings of your salvation, in whom, I say, having also believed, ye were sealed with the Holy Spirit that was promised,
Ephesians 4:30
and grieve not the Holy Spirit of God, whereby ye were sealed unto the day of redemption.
1 John 4:13
Hereby we know that we dwell in him, and he in us, because he hath given us of his Spirit.

With our

2 Corinthians 1:12
For our glorying is this, the testimony of our conscience, that in simplicity and the sincerity which is of God, not in fleshly wisdom, but in the grace of God, we have conducted ourselves in the world, and especially toward you.
1 John 3:19
And hereby we know that we are of the truth, and shall assure our hearts before him;
1 John 5:10
He that believeth in the Son of God hath the witness within him; he that believeth not God hath made him a liar, because he hath not believed in the witness which God hath borne concerning his Son.

General references

Galatians 3:26
For ye are all sons of God through faith in Christ Jesus;