That's like asking how do I know what Mark Twain or William Shakespears says? It's not hard to read the text and know what something says.
Do you defer to an expert, a pastor, someone more studied than you or do you reply only on your gut feelings?
I guess some go on their "gut" feelings.
So are you saying that all people who read Scripture should reach the same conclusion and that agree with you are inerrant?
Absent any infallible authority every interpretation of Scripture is as valid as the next. By your own standard you cannot claim that any denomination, personal interpretation, or Catechism is wrong, including that of the Church.
So tell me, are you infallible? Are you infallibly certain that your interpretation of the whole Bible right and that you inerrantly understand it? Is Billy Graham, Charles Taze Russell, David Koresh, John Smyth, or Jean Calvin? Where you differ who is right and who is wrong?
We all agree that Scripture is inerrant, but what is the objective infallibility of the Bible without an infallible interpreter? Are you that interpreter or are you only able to discern what is wrong, not what is right?
These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so.
What a concept!
searching the Scriptures!
(I guess they hadn't learned yet to rely on the traditions of the Fathers yet.)