'Witness' in the Bible

For our witness does not come from error or from an unclean heart or from deceit:

For neither at any time used we flattering words, as ye know, nor a cloke of covetousness; God is witness:

You yourselves are witnesses--and God is witness--how holy and upright and blameless our dealings with you believers were.

Even as you saw how, like a father with his children, we were teaching and comforting you all, and giving witness,

And that no man may make attempts to get the better of his brother in business: for the Lord is the judge in all these things, as we said to you before and gave witness.