How can we be sure that the Gospel is true?

The certainty of the Gospel rests on God's faithfulness to fulfill His promises. In Galatians 3:15, Paul illustrates that human covenants cannot be annulled; much more, God's covenant with Abraham and His promises are secure. The Gospel was preached in advance to Abraham, showing that the plan of salvation through Christ was ordained by God long before. Therefore, our faith in the Gospel is grounded in the unbreakable covenant God has with His people, fulfilled in the life and work of Jesus Christ.