“There are some things in them that are hard to understand …”
Paul could be a difficult writer. Peter says as much, while affirming that the Holy Spirit carried along his fellow apostle throughout the authorial process.
It’s all too easy to point to examples in Paul’s epistles. The run-on sentences. The apparent digressions and rabbit trails. The practical instruction that turns out to be theology as well, and operates on two levels. It’s not exactly Christianity 101, but this is how God chose to reveal the mystery of Christ and the mystery of his church to the world. Who are we to say he should have done it differently?