Why is knowing Jesus Christ essential for fulfillment?

Ecclesiastes 2:25 suggests that the true joy of life is not found in material wealth or personal achievement but in a relationship with Jesus Christ. The sermon emphasizes that only Christ fulfilled the ultimate work by completing the salvation of His people, ultimately declaring, 'It is finished' at Calvary. The preacher points out that without Christ, our pursuits are like vanity, endlessly unfulfilling. True contentment comes from embracing Christ and recognizing His work and purpose for us, leading to everlasting joy.