Arminian theologian Roger Olson is appealing to the witness of the Spirit as a safety net, which makes it okay to deny the inerrancy of Scripture. But that’s incoherent:
i) Our direct knowledge regarding the person and work of the Holy Spirit comes from the Bible. So you can’t cite the witness of the Spirit to salvage your denial of Biblical inerrancy, for your understanding of the Spirit is, itself, contingent on the veracity of Scripture. So the witness of the Spirit can’t protect you against an errant Bible.
ii) The Holy Spirit is the primary author of Scripture. To invoke the witness of the Spirit to rationalize an attack on the plenary, verbal inspiration of Scripture is an attack on the work of the Spirit.
iii) Scripture forewarns us to distinguish between competing spirits:
Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world (1 Jn 4:1).
You can’t invoke the Spirit to justify an attack on the Bible, for Word and Spirit don’t function independently. It’s a mutual witness. You can’t set them at odds. Without the one you lack the other.
Olson’s position reveals the state of modern Arminian theology, and it isn’t pretty.