Romans 1:9
for God is my witness, to whom I am entirely devoted, in preaching the gospel of his son, that I constantly make mention of you, in my prayers, requesting,
Romans 9:1
I call Christ, and the holy spirit to witness with my conscience, that I speak the truth without guile, when I say,
2 Corinthians 1:23
I call God to witness, and may I die if it is not true, that the reason of my not coming yet to Corinth, was to avoid using any severity towards you.
2 Corinthians 11:31
the ever-blessed God, and father of our Lord Jesus Christ, knows that I speak truth.
1 Thessalonians 2:5
our address to you was without any flattery, as you yourselves can witness, and God is witness that we had no avarice to disguise.
1 Thessalonians 2:10
you are witnesses, and God is so too, how holy, how just and irreproachable our behaviour was to you, who believe.