Romans 9:1

I speak the truth in Christ, I lie not, my conscience bearing me witness in the Holy Ghost,

Galatians 1:20

Which things moreover I write unto you, behold, before God, that I lie not.

1 Timothy 2:7

in which I have been placed a herald and an apostle I speak the truth, I lie not, a teacher of the Gentiles in faith and in truth.

Romans 1:9

For God is my witness, whom I serve in my spirit in the gospel of his Son, how I unceasingly make mention of you always in my prayer;

Romans 8:16

The Spirit Himself witnesses along with our spirit, that we are the children of God.

2 Corinthians 11:10

The truth of Christ is in me, that this glorying shall not cease unto me in the regions of Achaia.

2 Corinthians 12:19

For a long time you were thinking that I am apologizing to you. We speak before God in Christ; but all things, beloved, are for your edification.

Romans 2:15

who show the work of the law written in their hearts, their conscience witnessing, and their thoughts accusing or indeed excusing with one another,

2 Corinthians 1:12

For our boasting is this, the testimony of our conscience, that in holiness and purity of God, not in carnal wisdom, but in the grace of God, we have sojourned in the world, and especially towards you.

2 Corinthians 1:23

But I call God to witness to my soul, that sparing you I did not yet come into Corinth:

2 Corinthians 11:31

The God and Father of our Lord Jesus Christ, the one being blessed forever, knows that I lie not.

Philippians 1:8

For God is my witness, how I long after you in the affections of Jesus Christ.

1 Thessalonians 2:5

For at that time we were not in word of flattery, as you know, nor in a pretext of covetousness, God is our witness;

1 Timothy 1:5

but the end of the commandment is divine love out of a clean heart and a good conscience and faith free from hypocrisy:

1 Timothy 5:21

I testify before God, and Jesus Christ, and the elect angels, that you must guard these things without prejudice, doing nothing by partiality.

1 John 3:19-21

And in this we shall know that we are of the truth, and we shall assure our hearts before him;

Treasury of Scripture Knowledge

Summary

I say the truth in Christ, I lie not, my conscience also bearing me witness in the Holy Ghost,

General references

Bible References

I say

Romans 1:9
For God is my witness, whom I serve in my spirit in the gospel of his Son, how I unceasingly make mention of you always in my prayer;
2 Corinthians 1:23
But I call God to witness to my soul, that sparing you I did not yet come into Corinth:
2 Corinthians 11:31
The God and Father of our Lord Jesus Christ, the one being blessed forever, knows that I lie not.
2 Corinthians 12:19
For a long time you were thinking that I am apologizing to you. We speak before God in Christ; but all things, beloved, are for your edification.
Galatians 1:20
Which things moreover I write unto you, behold, before God, that I lie not.
Philippians 1:8
For God is my witness, how I long after you in the affections of Jesus Christ.
1 Thessalonians 2:5
For at that time we were not in word of flattery, as you know, nor in a pretext of covetousness, God is our witness;
1 Timothy 2:7
in which I have been placed a herald and an apostle I speak the truth, I lie not, a teacher of the Gentiles in faith and in truth.
1 Timothy 5:21
I testify before God, and Jesus Christ, and the elect angels, that you must guard these things without prejudice, doing nothing by partiality.

My conscience

Romans 2:15
who show the work of the law written in their hearts, their conscience witnessing, and their thoughts accusing or indeed excusing with one another,
Romans 8:16
The Spirit Himself witnesses along with our spirit, that we are the children of God.
2 Corinthians 1:12
For our boasting is this, the testimony of our conscience, that in holiness and purity of God, not in carnal wisdom, but in the grace of God, we have sojourned in the world, and especially towards you.
1 Timothy 1:5
but the end of the commandment is divine love out of a clean heart and a good conscience and faith free from hypocrisy:
1 John 3:19
And in this we shall know that we are of the truth, and we shall assure our hearts before him;

General references

Acts 24:16
In this I also exercise, to always have a conscience void of offense toward God and men.