John 3:33

Whoever receives His testimony has set his seal [of approval] to this: God is true [and he knows that God cannot lie].

John 6:27

Do not work for food that perishes, but for food that endures [and leads] to eternal life, which the Son of Man will give you; for God the Father has authorized Him and put His seal on Him.”

Romans 3:3-4

What then? If some did not believe or were unfaithful [to God], their lack of belief will not nullify and make invalid the faithfulness of God and His word, will it?

Romans 4:18-21

In hope against hope Abraham believed that he would become a father of many nations, as he had been promised [by God]: “So [numberless] shall your descendants be.”

2 Corinthians 1:18

But [as surely as] God is faithful and means what He says, our message to you is not “Yes” and “No” [at the same time].

2 Corinthians 1:22

it is He who has also put His seal on us [that is, He has appropriated us and certified us as His] and has given us the [Holy] Spirit in our hearts as a pledge [like a security deposit to guarantee the fulfillment of His promise of eternal life].

Ephesians 1:13

In Him, you also, when you heard the word of truth, the good news of your salvation, and [as a result] believed in Him, were stamped with the seal of the promised Holy Spirit [the One promised by Christ] as owned and protected [by God].

Titus 1:1-2

Paul, a bond-servant of God and an apostle (special messenger, personally chosen representative) of Jesus Christ, for the faith of God’s chosen ones and [to lead and encourage them to recognize and pursue] the knowledge of the truth which leads to godliness,

Hebrews 6:17

In the same way God, in His desire to show to the heirs of the promise the unchangeable nature of His purpose, intervened and guaranteed it with an oath,

1 John 5:9-10

If we accept [as we do] the testimony of men [that is, if we are willing to take the sworn statements of fallible humans as evidence], the testimony of God is greater [far more authoritative]; for this is the testimony of God, that He has testified regarding His Son.

Revelation 7:3-8

saying, “Do not harm the earth nor the sea nor the trees until we seal (mark) the bond-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
What then? If some did not believe or were unfaithful [to God], their lack of belief will not nullify and make invalid the faithfulness of God and His word, will it?
Romans 4:18
In hope against hope Abraham believed that he would become a father of many nations, as he had been promised [by God]: “So [numberless] shall your descendants be.”
2 Corinthians 1:18
But [as surely as] God is faithful and means what He says, our message to you is not “Yes” and “No” [at the same time].
Titus 1:1
Paul, a bond-servant of God and an apostle (special messenger, personally chosen representative) of Jesus Christ, for the faith of God’s chosen ones and [to lead and encourage them to recognize and pursue] the knowledge of the truth which leads to godliness,
Hebrews 6:17
In the same way God, in His desire to show to the heirs of the promise the unchangeable nature of His purpose, intervened and guaranteed it with an oath,
1 John 5:9
If we accept [as we do] the testimony of men [that is, if we are willing to take the sworn statements of fallible humans as evidence], the testimony of God is greater [far more authoritative]; for this is the testimony of God, that He has testified regarding His Son.