How do we know we are adopted as God's children?

Paul affirms in Galatians 4:6 that because we are sons, God has sent forth the Spirit of His Son into our hearts, crying 'Abba, Father.' This internal testimony of the Spirit reassures believers of their status as God's children. Romans 8:14-16 further supports this, stating, 'For as many as are led by the Spirit of God, they are the sons of God.' The Spirit bears witness with our spirit that we are indeed children of God, enabling believers to cry out in intimacy and trust to their Heavenly Father, securing their place in His family.