'Witness' in the Bible

I call God to witness--to whom I render priestly and spiritual service by telling the Good News about His Son-- how unceasingly I make mention of you in His presence,

since they exhibit proof that a knowledge of the conduct which the Law requires is engraven on their hearts, while their consciences also bear witness to the Law, and their thoughts, as if in mutual discussion, accuse them or perhaps maintain their innocence--

But now a righteousness coming from God has been brought to light apart from any Law, both Law and Prophets bearing witness to it--

The Spirit Himself bears witness, along with our own spirits, to the fact that we are children of God;

For I bear witness that they possess an enthusiasm for God, but it is an unenlightened enthusiasm.