Complex sentence: Thereafter he was made aware of such secrets of'spiritual heights' as could not be comprehended merely by human wit and intelligence and declared that he no longer had any control over this book, but that it was God alone who knew how it would proceed.
Split into simpler sentences: Thereafter he was made aware of such secrets of'spiritual heights' as could not be comprehended merely by human wit and intelligence. With this he declared that he no longer had any control over this book, but that it was God alone who knew how it would proceed.