How do we know that we are saved according to the doctrine of adoption?

The doctrine of adoption confirms our salvation through the inner testimony of the Holy Spirit. In Romans 8:15, Paul contrasts the spirit of bondage with the spirit of adoption, which reflects the internal change that occurs at true conversion. When God initiates the work of salvation, He first reveals our state of bondage to sin, leading to a fear of His judgment. However, once we are reconciled to Him, He grants us the spirit of adoption, allowing us to call Him 'Abba, Father.' This direct relationship signifies that we are recognized as God's children, and the assurance that follows from this intimate connection can affirm our salvation. It's not by our works or efforts, but by God's grace that we are adopted into His family (Ephesians 1:4-5).