Jesus did speak of the things kept secret since the foundation of the world.
However, he spoke of these things in parables.
This proves that it was Christ Jesus who first preached the mysteries kept secret since the foundation of the world, and NOT Paul.
Paul was made privy to the mystery. You need to study/read Romans
through Philemon to find what truths you need to establish in your own
life. Which I highly doubt you will? You're a brainwashed Preterist and
see things in that vain.