Why is the concept of God's faithfulness important for Christians?

Understanding God's faithfulness is vital for Christians, as it shapes our trust in His promises. As stated in 1 Corinthians 1:9, 'God is faithful, by whom you were called.' This means that God's faithfulness undergirds not only our salvation but also His continual work in our lives. His promises are sure; He will not abandon those who He has called. Romans 11:29 states that the gifts and calling of God are irreversible, underscoring that once called, we are securely kept by His grace. The assurance of His faithfulness encourages believers to remain steadfast in faith, knowing that God will complete the work He has begun in us (Philippians 1:6).