John 3:33

He that hath received his testimony, hath set to his seal, that God is true.

John 6:27

Labour not for the meat which perisheth, but for that which endureth to everlasting life, which the Son of man will give you; for him hath God the Father sealed.

Romans 3:3-4

For what if some believed not? Shall their unbelief disannul the faithfulness of God?

Romans 4:18-21

Who against hope believed in hope, that he should be the father of many nations, according to that which was spoken, So shall thy seed be.

2 Corinthians 1:18

As God is faithful, our word to you hath not been yea and nay.

2 Corinthians 1:22

Who hath also sealed us, and given us the earnest of the Spirit in our hearts.

Ephesians 1:13

In whom ye likewise believed, after ye had heard the word of truth, the gospel of your salvation; in whom having believed, ye were also sealed by that Holy Spirit of promise,

Titus 1:1-2

Paul a servant of God, and an Apostle of Jesus Christ, in things concerning the faith of God's elect, and the knowledge of the truth which is after godliness,

Hebrews 6:17

Wherefore God being willing to shew more abundantly to the heirs of the promise the unchangeableness of his counsel, interposed by an oath:

1 John 5:9-10

If we receive the testimony of men, the testimony of God is greater; and this is the testimony of God, which he hath testified of his Son.

Revelation 7:3-8

Saying, Hurt ye not the earth, neither the sea, neither the trees, till we seal the servants of our God on their foreheads.

Treasury of Scripture Knowledge

Summary

He that hath received his testimony hath set to his seal that God is true.

Bible References

Hath set

Romans 3:3
For what if some believed not? Shall their unbelief disannul the faithfulness of God?
Romans 4:18
Who against hope believed in hope, that he should be the father of many nations, according to that which was spoken, So shall thy seed be.
2 Corinthians 1:18
As God is faithful, our word to you hath not been yea and nay.
Titus 1:1
Paul a servant of God, and an Apostle of Jesus Christ, in things concerning the faith of God's elect, and the knowledge of the truth which is after godliness,
Hebrews 6:17
Wherefore God being willing to shew more abundantly to the heirs of the promise the unchangeableness of his counsel, interposed by an oath:
1 John 5:9
If we receive the testimony of men, the testimony of God is greater; and this is the testimony of God, which he hath testified of his Son.