'Bears Witness' in the Bible

There is another who bears witness of me, and I know that the testimony which he bears of me is true.

I am One who bears witness of myself, and the Father who sent me bears witness of me."

The Spirit himself bears witness with our spirit that we are children of God,

And the Holy Spirit also bears witness to us; for after saying,

And it is the Spirit who bears witness, because the Spirit is the truth.