There are two facts about human existence that nearly all religions, worldviews, philosophies, and ideologies agree. We are finite and we are fallen. The existence of evil and human limitation are uncontested facts of reality.
Psalm 90, the only psalm attributed to Moses, is an excellent discourse about human nature, according to the biblical worldview.
Verses 3–6 declare the following about the finite and transient nature of human beings:
You return man to dust and say, “Return, O children of man!” For a thousand years in your sight are but as yesterday when it is past, or as a watch in the night.
You sweep them away as with a flood; they are like a dream, like grass that is renewed in the morning: in the morning it flourishes and is renewed; in the evening it fades and withers.
We are finite. Clearly, we cannot overcome our basic limitations. We cannot completely eliminate our lack of experience or limitations of intellect. We cannot change the facts of our birth, ethnic heritage, and many other facets and weaknesses of our personal identity. We are not qualified in the quantity or quality of knowledge or character to be God.
Psalm 90 provides two metaphors that illustrate how fleeting life is. First, we are “dust creatures.” In the Bible to be “in the dust” is a metaphor indicating a status of poverty and powerlessness. On the other hand, to be “raised from the dust” means to be given honor and power. Listen to how the Psalms describes both nuances:
These all [animals] look to you to give them their food at the proper time. When you give it to them, they gather it up; when you open your hand, they are satisfied with good things. When you hide your face, they are terrified; when you take away their breath, they die and return to the dust. (Ps 104:27–29)
He raises the poor from the dust and lifts the needy from the ash heap; he seats them with princes, with the princes of their people. He settles the barren woman in her home as a happy mother of children. Praise the LORD. (Ps 113:7)
The dust metaphor teaches that we have nothing apart from God. We are worthless apart from his goodness and grace. And, just as God breathed life into the first “dust creature,” Adam, he breathes life into each of us in Christ. These verses clearly indicate that God is sovereign over our lives. It is he who says “return to dust.”
The second metaphor is “grass.” In light of eternity our lives are fleeting and short. Psalm 102 echoes the contrast between God and mankind expressed in Psalm 90: “My days are like the evening shadow; I wither away like grass. But you, O LORD, sit enthroned forever; your renown endures through all generations” (vs 11–12).
Again, according to the biblical worldview we are finite. Psalm 90 shows that the wise person knows this and knows how to respond to this critical fact about reality.