Your opinion was never in question here. What the Bible says is the issue, and this verse says nothing more than Scripture is required for completion. It does NOT say Scripture accomplishes completion all by itself, nor does it say how much Scripture Paul was referring to as "all."
How could the man of God be complete before all of Scripture, as we count it, was codified at the time Paul wrote this admonition?
The verse says Scripture gives us enough to make us perfect...what could be more compete then perfection.
The scripture that this verse is referring too was the OT scripture. The OT scripture tells tells how the people before scripture was written were saved. They trusted God. They looked forward to the Saviors coming, we look back to it.
Becky