How do we know God chooses some and rejects others?

In Romans 9:10-13, Paul explicates the doctrine of God's sovereignty in election, referencing Jacob and Esau to demonstrate God's unmerited love towards one and rejection of the other. The phrase 'Jacob have I loved, but Esau have I hated' highlights the divine prerogative where God's choices transcend human reasoning or merit. This doctrine reassures believers that salvation is not based on personal merit but solely on God's gracious choice and purpose. Esau's rejection serves to illustrate the seriousness of indifference toward spiritual matters and how God's eternal plans unfold according to His will, irrespective of human understanding.