What does the Bible say about the vanity of human efforts?

Ecclesiastes asserts that all human endeavors and pursuits, no matter how noble or significant, are vanity when examined through a spiritual lens (Ecclesiastes 1:2). The Preacher, traditionally understood to be Solomon, emphasizes that all labor is meaningless under the sun if it is not rooted in a relationship with God. This perspective reminds believers that true fulfillment and purpose can only be found in Christ, who alone provides eternal significance to our works, as all other efforts will ultimately perish.