Tā yòng jiǎndān de yǔyán jiěshì le shēn'ào de dàolǐ.
He explained profound truths in simple language.
Tips
usage
深奥 describes abstract, intellectual difficulty - philosophy, science, theory. Don't use it for physically difficult tasks. Compare with 深刻 (shēnkè, 'profound/deep') which describes impact or insight rather than difficulty.
