John 3:33

he who is receiving his testimony did seal that God is true;

John 6:27

work not for the food that is perishing, but for the food that is remaining to life age-during, which the Son of Man will give to you, for him did the Father seal -- even God.'

Romans 3:3-4

for what, if certain were faithless? shall their faithlessness the faithfulness of god make useless?

Romans 4:18-21

Who, against hope in hope did believe, for his becoming father of many nations according to that spoken: 'So shall thy seed be;'

2 Corinthians 1:18

and God is faithful, that our word unto you became not Yes and No,

2 Corinthians 1:22

who also sealed us, and gave the earnest of the Spirit in our hearts.

Ephesians 1:13

in whom ye also, having heard the word of the truth -- the good news of your salvation -- in whom also having believed, ye were sealed with the Holy Spirit of the promise,

Titus 1:1-2

Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of the choice ones of God, and an acknowledging of truth that is according to piety,

Hebrews 6:17

in which God, more abundantly willing to shew to the heirs of the promise the immutability of his counsel, did interpose by an oath,

1 John 5:9-10

If the testimony of men we receive, the testimony of God is greater, because this is the testimony of God that He hath testified concerning His Son.

Revelation 7:3-8

'Do not injure the land, nor the sea, nor the trees, till we may seal the servants of our God upon 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 certain were faithless? shall their faithlessness the faithfulness of god make useless?
Romans 4:18
Who, against hope in hope did believe, for his becoming father of many nations according to that spoken: 'So shall thy seed be;'
2 Corinthians 1:18
and God is faithful, that our word unto you became not Yes and No,
Titus 1:1
Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of the choice ones of God, and an acknowledging of truth that is according to piety,
Hebrews 6:17
in which God, more abundantly willing to shew to the heirs of the promise the immutability of his counsel, did interpose by an oath,
1 John 5:9
If the testimony of men we receive, the testimony of God is greater, because this is the testimony of God that He hath testified concerning His Son.