Romans 1:9
For God is my witness, whom I serve with my spirit in the gospel of his Son, that without ceasing I mention you always in my prayers,
Romans 9:1
I am speaking the truth in Christ, I am not lying; my conscience bears me witness in the Holy Spirit,
2 Corinthians 1:23
But I call God as my witness that it was in order to spare you that I did not return to Corinth.
2 Corinthians 11:31
The God and Father of the Lord Jesus, he who is blessed forever, knows that I am not lying.
1 Thessalonians 2:5
For, as you know, we never used flattery nor a pretext for greed God is witness
1 Thessalonians 2:10
You are witnesses, and God also, how holy and righteous and blameless we behaved toward you believers;