Romans 9:1

I am telling the truth as a Christian man. I am telling no lie, because my conscience enlightened by the Holy Spirit is bearing me witness to this fact,

Galatians 1:20

In writing you this, I swear before God, I am telling you the solemn truth.

1 Timothy 2:7

and for which purpose I was appointed a preacher and an apostle -- I am telling the truth, I am not lying, -- a teacher of the heathen in the realm of faith and truth.

Romans 1:9

Indeed, my witness is God, whom I serve in my spirit by telling the good news about His Son, that I never fail to mention you every time I pray,

Romans 8:16

The Spirit Himself bears witness with our spirits that we are God's children;

2 Corinthians 11:10

But the truth of Christ in me, this boasting of mine shall never be stopped in the boundaries of Greece.

2 Corinthians 12:19

Are you thinking all this time that I am defending myself to you? It is in the very presence of God and as one who is in union with Christ that I am speaking. And it is all for building you up, beloved, for I am apprehensive that, somehow or other, when I come I shall find you not as I want to find you, and that you may find me not as you want to find me.

Romans 2:15

for they show that the deeds the law demands are written on their hearts, because their consciences will testify for them, and their inner thoughts will either accuse or defend them,

2 Corinthians 1:12

For my boast is this, to which my conscience testifies, that before the world, but especially before you, I have acted from pure motives and in sincerity before God, not depending on worldly wisdom but on God's unmerited favor.

2 Corinthians 1:23

But upon my soul I call God to witness that it was to spare you pain that I gave up my visit to Corinth.

2 Corinthians 11:31

The God and Father of the Lord Jesus, who is blessed forever, knows that I am telling the truth.

Philippians 1:8

For God is my witness how I never stop yearning for all of you with the affection Christ Jesus inspires.

1 Thessalonians 2:5

Indeed, we never resorted to flattery, as you are well aware, nor to any pretext for making money; God is our witness.

1 Timothy 1:5

But the aim of your instruction is to be love that flows out of a pure heart, a good conscience, and a sincere faith.

1 Timothy 5:21

I solemnly charge you before God and Christ Jesus and the chosen angels, to carry out these instructions without prejudice and with perfect impartiality.

1 John 3:19-21

In this way we shall know by experience that we are on the side of the truth, and satisfy our consciences in God's sight,

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
Indeed, my witness is God, whom I serve in my spirit by telling the good news about His Son, that I never fail to mention you every time I pray,
2 Corinthians 1:23
But upon my soul I call God to witness that it was to spare you pain that I gave up my visit to Corinth.
2 Corinthians 11:31
The God and Father of the Lord Jesus, who is blessed forever, knows that I am telling the truth.
2 Corinthians 12:19
Are you thinking all this time that I am defending myself to you? It is in the very presence of God and as one who is in union with Christ that I am speaking. And it is all for building you up, beloved, for I am apprehensive that, somehow or other, when I come I shall find you not as I want to find you, and that you may find me not as you want to find me.
Galatians 1:20
In writing you this, I swear before God, I am telling you the solemn truth.
Philippians 1:8
For God is my witness how I never stop yearning for all of you with the affection Christ Jesus inspires.
1 Thessalonians 2:5
Indeed, we never resorted to flattery, as you are well aware, nor to any pretext for making money; God is our witness.
1 Timothy 2:7
and for which purpose I was appointed a preacher and an apostle -- I am telling the truth, I am not lying, -- a teacher of the heathen in the realm of faith and truth.
1 Timothy 5:21
I solemnly charge you before God and Christ Jesus and the chosen angels, to carry out these instructions without prejudice and with perfect impartiality.

My conscience

Romans 2:15
for they show that the deeds the law demands are written on their hearts, because their consciences will testify for them, and their inner thoughts will either accuse or defend them,
Romans 8:16
The Spirit Himself bears witness with our spirits that we are God's children;
2 Corinthians 1:12
For my boast is this, to which my conscience testifies, that before the world, but especially before you, I have acted from pure motives and in sincerity before God, not depending on worldly wisdom but on God's unmerited favor.
1 Timothy 1:5
But the aim of your instruction is to be love that flows out of a pure heart, a good conscience, and a sincere faith.
1 John 3:19
In this way we shall know by experience that we are on the side of the truth, and satisfy our consciences in God's sight,

General references

Acts 24:16
So I am always striving to have a conscience that is clear before God and men.