Eventually you will yes. The “guarantee” part comes if you discard anything someone says that can’t be confirmed with scripture. Hold someone or some entity as “authoritative” and you will quell the influence of the Holy Spirit and the guarantee is voided.
Oh....eventually. Interesting. So--assuming neither of us is infallible in their Scriptural exegesis, which I'm sure you'll agree with--how come it's me that will eventually agree with your position, and not you that will eventually agree with mine?
It also has to do with the object of one’s faith. If a Muslim searches the NT looking for the 5 pillars of Islam they will be sorely disappointed.