Ecclesiastes is a difficult book to classify because although it's in the Bible, it's not really all that theological. It's mostly a collection of Solomon's world views rather than his spiritual knowledge.
Ecclesiastes is the Bible's fun book because it's chock full of normal thinking instead of religious dogma. Ecclesiastes requires very little interpretation as anybody who's been around the block a time or two can easily relate to its thoughts.
Solomon composed his comments from the perspective of a philosophical man who's understanding of life and the hereafter is moderated by empirical evidence and the normal round of human experience. It's a handy book of the Bible for showing that not all religious people are kooks with their heads in the clouds and unable to see things as they are through the eyes of normal people.
Just a word of caution: According to Matt 12:42, Luke 11:31, John 1:1-14, and Col 2:3; Christ trumps Solomon, so beware of using proof texts from Ecclesiastes to impair, moderate, and/or water down Christ's teachings related to the afterlife.
In addition: Christ is the voice of God (John 3:34, John 8:26, John 8:28, John 12:49, John 14:24) whereas there is not the slightest textual evidence in the book of Ecclesiastes that Solomon was anybody's voice but his own when he wrote it.
To my knowledge, Solomon had never seen the afterlife for himself, viz: he wasn't an expert witness; whereas Christ had seen the afterlife for himself and knew what he was talking about.
● John 3:31-32 . . He who comes from above is above all, he who is of the earth is from the earth and speaks of the earth. He who comes from heaven is above all. What He has seen and heard, of that he bears witness.
Christ is also highly recommended, whereas to my knowledge, Solomon isn't.
● Matt 17:5 . . This is my Son, the beloved, whom I have approved; listen to him.
So then, when encountering remarks in the book of Ecclesiastes that are out of step with Christ's teachings in the New Testament; my unsolicited spiritual counseling is to ignore Solomon and go with the wisdom of "my Son".
● John 8:12 . . I am the light of the world. He that follows me will by no means walk in darkness, but will possess the light of life.
FAQ: Doesn't the apostle Paul say that all Scripture is God breathed?
A: There is a difference between inspiration and dictation.
Solomon was no doubt inspired to record his personal world view in the book of Ecclesiastes, but we shouldn't assume his world view quotes God word-for-word the way Christ does.
01 02 03 04 05 06
07 08 09 10 11 12
for Psalm 70