Ecclesiastes 12:14 - Ellicott's Commentary On The Whole Bible

Considering that the book is filled with complaints of the imperfection of earthly retribution, this announcement of a tribunal, at which “every work,” “every secret thing,” shall be brought into judgment, cannot be reasonably understood of anything but a judgment after this life; so that this book, after all its sceptical debatings, ends by enunciating, more distinctly than is done elsewhere in the Old Testament, the New Testament doctrine of a day when God shall judge the secrets of men (Romans 2:16), shall bring to light the hidden things of darkness, and make manifest the counsels of the hearts (1 Corinthians 4:5).