“The Spirit himself bears witness to our spirit that we are God’s children.”
The statement above is part of an argument of Paul’s about our inheritance with Christ. He does not affirm the manner of the Spirit’s witness. But it must be a discernible, objective one, not some inner, subjective one, whether by his Word or by the production of his fruit in a Christian’s life.
We do not want to reduce the Spirit down to only the Bible, as some do. His witness is personal and real. His action continues today. Still, “let’s interpret our experiences by the Bible, and not the Bible by our experiences” (Mark Dunagan).