Problem: The Bible teaches that the soul survives death (Phil. 1:23; 2 Cor. 5:8; Rev. 6:9). But, Ecclesiastes insists that “all go to one place: all are from the dust, and all return to dust” (v. 20). Hence, “man has no advantage over beasts, for all is vanity” (Ecclesiastes 3:19).
Solution: The reference here is to the human body, not to the soul. Both men and beast die and their bodies return to dust. However, humans are different in that their soul “goes upward” (v. 21). In fact, Solomon speaks of “eternity” in the human heart (Ecc. 3:11) and of its immortality when he declares that at death “man goes to his eternal home” (12:5). He also emphasized that we should fear God because there is a day when “God will bring you into judgment” after this life (11:9). So Ecclesiastes is not denying life after death; it is warning about the futility of living only for this life “under the sun” (cf. 1:3, 13; 2:18). (See prior comments under Ecclesiastes 3:19.)