How do we know God's grace is unmerited?

The concept of unmerited grace is fundamental in Reformed theology, exemplified in Romans 11:6, where Paul writes that if it is by grace, it is no longer by works; otherwise grace would no longer be grace. This highlights that grace is purely an unearned favor from God. It emphasizes that salvation and relationship with God are not products of human merit or adherence to law but are solely initiated by God's kindness and mercy towards humanity. Hence, our standing before God is exclusively owing to His grace, illustrating the beauty of 'amazing grace' that saves 'a wretch like me.'