All the more reason to test the spirits by the Word of God, instead of discounting His Word. The Holy Spirit glorifies the Son.
I don’t know where you get that anyone is discounting the word of God. We Catholics believe that all scripture is inspired by the Holy Spirit.
We also believe the Holy Spirit guides His Church in properly understanding the Word, as pointed out in the article, to avoid the confusion of doctrines (Doctrines of men) in the hundreds or even thousands of Protestant sects, none of which agree on many details, and which all claim to be based on Holy Scripture alone.