Ecclesiastes is customarily read during Sukkot, the festival of Booths or Tabernacles, to pour a bucket of reality on the rejoicing of the promised time when God will dwell with mankind.
We look for an explanation for the misery and battle between good, bad and evil explored in the book of Ecclesiastes both from the beginning of history and the end. Revelation 21–22 assures us that God will wipe away all tears and there will be no death, mourning, pain or frustration. All those things will pass away. That is what we are all looking forward to when Yeshua will tabernacle with men forever.