1 John 3:19

In this way we may be certain that we are true, and may give our heart comfort before him,

Isaiah 32:17

And the work of righteousness will be peace; and the effect of an upright rule will be to take away fear for ever.

John 13:35

By this it will be clear to all men that you are my disciples, if you have love one for another.

John 18:37

Then Pilate said to him, Are you then a king? Jesus made answer, You say that I am a king. For this purpose was I given birth, and for this purpose I came into the world, that I might give witness to what is true. Every lover of what is true gives ear to my voice.

Romans 4:21

And being certain that God was able to keep his word.

Romans 8:38

For I am certain that not death, or life, or angels, or rulers, or things present, or things to come, or powers,

2 Timothy 1:12

And for which I undergo these things: but I have no feeling of shame. For I have knowledge of him in whom I have faith, and I am certain that he is able to keep that which I have given into his care till that day.

Hebrews 6:10-11

For God is true, and will not put away from him the memory of your work and of your love for his name, in the help which you gave and still give to the saints.

Hebrews 10:22

Let us go in with true hearts, in certain faith, having our hearts made free from the sense of sin and our bodies washed with clean water:

Hebrews 11:13

All these came to their end in faith, not having had the heritage; but having seen it with delight far away, they gave witness that they were wanderers and not of the earth.

1 John 1:8

If we say that we have no sin, we are false to ourselves and there is nothing true in us.

1 John 3:14

We are conscious that we have come out of death into life because of our love for the brothers. He who has no love is still in death.

1 John 3:21

My loved ones, if our heart does not say that we have done wrong, we have no fear before him;

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
My loved ones, if our heart does not say that we have done wrong, we have no fear before him;
Isaiah 32:17
And the work of righteousness will be peace; and the effect of an upright rule will be to take away fear for ever.
Hebrews 6:10
For God is true, and will not put away from him the memory of your work and of your love for his name, in the help which you gave and still give to the saints.
Hebrews 10:22
Let us go in with true hearts, in certain faith, having our hearts made free from the sense of sin and our bodies washed with clean water:

Assure

Romans 4:21
And being certain that God was able to keep his word.
Romans 8:38
For I am certain that not death, or life, or angels, or rulers, or things present, or things to come, or powers,
2 Timothy 1:12
And for which I undergo these things: but I have no feeling of shame. For I have knowledge of him in whom I have faith, and I am certain that he is able to keep that which I have given into his care till that day.
Hebrews 11:13
All these came to their end in faith, not having had the heritage; but having seen it with delight far away, they gave witness that they were wanderers and not of the earth.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain