What is at the core of the secrets and mysteries Paul received and taught?
At the core of the secrets and mysteries Paul received and taught is the Gospel: that Christ died for our sins according to the Scriptures, was buried, and rose again the third day according to the Scriptures. This was pre-planned before creation, addressing man's sin and need of a Savior and Redeemer.
Les teaches that the Gospel is not merely a part of Scripture but the message by which a person is saved if they truly believe and do not believe in vain. He points to 1 Corinthians 15:1-4, where Paul declares the Gospel he preached, which the Corinthians received and in which they stand. Paul delivered what he also received. Les connects this to Paul's Damascus road experience: the ascended, glorified Lord, not Jesus of Nazareth in His earthly ministry, stopped the religious renegade Jew, saved him by grace, and revealed this Gospel to him in the desert. That Gospel is that Christ died for our sins according to the Scriptures, was buried, and rose again the third day according to the Scriptures. Les says this was all pre-planned before anything was created: God would create man, man would sin and need a Savior and Redeemer. God set everything in motion, brought about Christ's earthly ministry, crucifixion, and resurrection, and brought Him back to heaven, from which He revealed these things Paul calls the Secrets or Mysteries. The very core of that is the Gospel, that Christ died for our sins.