NIV 1 Corinthians 2:11-16
11. For who among men knows the thoughts of a man except the man's spirit within him? In the same way no one knows the thoughts of God except the Spirit of God.
12. We have not received the spirit of the world but the Spirit who is from God, that we may understand what God has freely given us.
13. This is what we speak, not in words taught us by human wisdom but in words taught by the Spirit, expressing spiritual truths in spiritual words.
14. The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually discerned.
15. The spiritual man makes judgments about all things, but he himself is not subject to any man's judgment:
16. "For who has known the mind of the Lord that he may instruct him?" But we have the mind of Christ.NIV Romans 15:21
Rather, as it is written: "Those who were not told about him will see, and those who have not heard will understand."NIV 2 Corinthians 1:13-14
13. For we do not write you anything you cannot read or understand. And I hope that,
14. as you have understood us in part, you will come to understand fully that you can boast of us just as we will boast of you in the day of the Lord Jesus.NIV Colossians 2:2-4
2. My purpose is that they may be encouraged in heart and united in love, so that they may have the full riches of complete understanding, in order that they may know the mystery of God, namely, Christ,
3. in whom are hidden all the treasures of wisdom and knowledge.
4. I tell you this so that no one may deceive you by fine-sounding arguments.NIV 2 Peter 3:15-16
15. Bear in mind that our Lord's patience means salvation, just as our dear brother Paul also wrote you with the wisdom that God gave him.
16. He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction.NIV 1 John 5:20
We know also that the Son of God has come and has given us understanding, so that we may know him who is true. And we are in him who is true--even in his Son Jesus Christ. He is the true God and eternal life.
Plain sense interpretations of scripture taken out of context don't convince me. These passages don't add up to the conclusion you make at the end.
The problem here is one of interpretation. I also believe that even for the Faithful "our finite minds cannot successfully accomplish the task, and that we will often get it wrong". This is because I don't think there is more than one true interpretation. Truth is objective and eternal.
When disputes arise, there needs to be an authority that settles the dispute. Over time a group dedicated and specifically educated and with the help of the Holy Spirit has the teaching authority to settle disputes. This provides the best method by which fallible humans can discern infallible teachings. The Apostle Peter did not believe scripture was for private interpretation. True teachers are the Apostles and those who have followed in the Apostolic succession.
If I decide to reject the teaching authority of two thousand years to go with my own interpretations then that would be me making my own truth.