'Adds' in the Bible

I am telling you the truth as a Christian man--it is no falsehood, for my conscience enlightened, as it is, by the Holy Spirit adds its testimony to mine--

Brethren, (I speak according to man,) even man's confirmed covenant no one sets aside, or adds other dispositions to.

He then adds, "I have come to do Thy will." He does away with the first in order to establish the second.

And the Holy Spirit also adds His testimony to us [in confirmation of this]; for after having said,

He adds:I will never again remembertheir sins and their lawless acts.

I testify to everyone who hears the prophetic words of this book: If anyone adds to them, God will add to him the plagues that are written in this book.