Why is it said that only believers can do good works?

The central tenet of sovereign grace theology is that good works can only be performed by those who have been regenerated by the Holy Spirit and justified by faith in Christ. As stated in Romans 7:5, prior to being born again, individuals lack the spiritual capacity to produce works that please God. Good works are rooted in a regenerate heart, empowered and motivated by the Holy Spirit, which aligns with the believer's new nature and aims for God's glory. Therefore, good works are not a means to earn salvation but are the result of a genuine response to God's grace in the believer's life.