'Witness' in the Bible

For God is my witness, whom I serve with my spirit in the gospel of his Son, that without ceasing I make mention of you always in my prayers;

Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;)

But now without law righteousness of God is manifested, borne witness to by the law and the prophets;

And he was given the sign of circumcision as a witness of the faith which he had before he underwent circumcision: so that he might be the father of all those who have faith, though they have not circumcision, and so that righteousness might be put to their account;

The Spirit itself beareth witness with our spirit, that we are the children of God:

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

For I bear them witness that they have zeal for God, but not according to knowledge.

For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself.