“God tests them.” There is much discussion among the scholars about the word “test,” but most commentators agree that “test” is in some sense the basic meaning of the Hebrew text. The context is about humans being an “animal” and dying like all the rest of the animals (Ecc. 3:19-20). That is true. Humans are not different from animals in our flesh and blood, nor in the soul life that animates us. Humans are only different from animals in that in certain ways we were created in the image of God (Gen. 1:26, but God certainly does not have flesh and bone). At death, both humans and animals are dead in every way and return to dust (Gen. 3:19; Ecc. 3:20).
These things are hard for most Christians to understand due to erroneous orthodox teaching. Orthodox Christianity teaches the humans have a soul but animals do not, which is not accurate: both humans and animals are animated by “soul.” Also, orthodox Christianity teaches that animals are dead when they die but humans live on after their body dies, but this also is inaccurate. As Ecclesiastes 3:18-21 teaches, humans are actually animals (v. 18), they both die the same way and have one “breath,” and in that sense humans have no advantage over any other animal (v. 19). One great advantage that humans do have over animals is that the part of us that is created in God’s image gives us a unique mind with faculties such as insight, wisdom, a sense of purpose, and a conscience. God created humans to fellowship with Him and live forever with Him, and so God will raise humans from the dead.
The “test” that God gives humans, in part at least, is that as we pay attention to the humans and animals in the world we live in, we should see that our lives are short (Ps. 103:15-16; James 4:14) and we cannot control the day we die (Ecc. 8:8). The sense of purpose that God has placed inside us should then nudge us to believe that we are not here on earth just to live a short, difficult life and then die. That awareness should motivate us to want to stay alive longer—actually, forever—and if we continue to press in our search, that will eventually lead us to the existence of a creator God who can grant us everlasting life. Thus, people who pass the test find God and salvation, and will live forever, while those who fail the test will be self-absorbed to the end that they do not seek God, do not get saved, and eventually perish.
[For more on “soul” animating humans and animals, see Appendix 7, “Usages of Soul.” For people being dead in every way when they die and only made alive when raised by God, see Appendix 4, “The Dead are Dead.” For more on unsaved humans eventually being like the animals and ceasing to exist in any form, see Appendix 5, “Annihilation in the Lake of Fire”].