1 John 3:19

Thus it is that we may be sure we belong to the truth and reassure ourselves

John 13:35

By this everyone will recognize that you are my disciples, if you have love one for another."

John 18:37

"So you are a king?" said Pilate, "you!" "Certainly," said Jesus, "I am a king. This is why I was born, this is why I came into the world, to bear testimony to the truth. Everyone who belongs to the truth listens to my voice."

Romans 4:21

and felt convinced that He was able to do what He had promised.

Romans 8:38

For I am certain neither death nor life, neither angels nor principalities, neither the present nor the future,

2 Timothy 1:12

and this is why I am suffering. Still, I am not ashamed of it; I know whom I have trusted and I am certain he is able to keep what I have put into his hands till the great Day.

Hebrews 6:10-11

God is not unfair; he will not forget what you have done, or the love you have shown for his sake in ministering, as you still do, to the saints.

Hebrews 10:22

let us draw near with a true heart, in absolute assurance of faith, our hearts sprinkled clean from a bad conscience, and our bodies washed in pure water;

Hebrews 11:13

(These all died in faith without obtaining the promises; they only saw them far away and hailed them, owning they were 'strangers and exiles upon earth.'

1 John 1:8

If we say, 'We are not guilty,' we are deceiving ourselves and the truth is not in us;

1 John 3:14

We know we have crossed from death to life, because we love the brotherhood; he who has no love [for his brother] remains in death.

1 John 3:21

If our heart does not condemn us, beloved, then we have confidence in approaching God,

Treasury of Scripture Knowledge

Summary

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

Bible References

Shall

1 John 3:21
If our heart does not condemn us, beloved, then we have confidence in approaching God,
Hebrews 6:10
God is not unfair; he will not forget what you have done, or the love you have shown for his sake in ministering, as you still do, to the saints.
Hebrews 10:22
let us draw near with a true heart, in absolute assurance of faith, our hearts sprinkled clean from a bad conscience, and our bodies washed in pure water;

Assure

Romans 4:21
and felt convinced that He was able to do what He had promised.
Romans 8:38
For I am certain neither death nor life, neither angels nor principalities, neither the present nor the future,
2 Timothy 1:12
and this is why I am suffering. Still, I am not ashamed of it; I know whom I have trusted and I am certain he is able to keep what I have put into his hands till the great Day.
Hebrews 11:13
(These all died in faith without obtaining the promises; they only saw them far away and hailed them, owning they were 'strangers and exiles upon earth.'