'Witnessing' in the Bible

And the night after, the Lord came to his side and said, Be of good heart, for as you have been witnessing for me in Jerusalem, so will you be my witness in Rome.

And so, by God's help, I am here today, witnessing to small and great, saying nothing but what the prophets and Moses said would come about;

The Holy Spirit witnessing by this that the way into the holy place had not at that time been made open, while the first Tent was still in being;

I have sent you this short letter by Silvanus, a true brother, in my opinion; comforting you and witnessing that this is the true grace of God; keep to it.

(And the life was made clear to us, and we have seen it and are witnessing to it and giving you word of that eternal life which was with the Father and was seen by us);