How do we know election is by grace?

The concept of election being by grace is strongly supported in Romans 11:5-6, where the Apostle Paul writes, 'even so then at this present time also there is a remnant according to the election of grace. And if by grace, then is it no more of works: otherwise grace is no more grace.' This emphasizes that God's choice of who will be saved is not based on any merit or action of the individual but wholly on His sovereign grace. If any work were considered as a condition, then it would nullify grace as a gift, illustrating that our salvation is entirely a result of God’s unmerited favor.