How do we know God's ability to save is true?

We can be assured of God's ability to save through His covenant faithfulness as illustrated in scripture. For example, God promised Abraham, Isaac, and Jacob that He would deliver their descendants from slavery in Egypt and bring them to a land flowing with milk and honey. Historical acts such as the Exodus and the miracles performed in the wilderness reinforce this promise. God's past actions give us firm confidence that He is capable of fulfilling His promises, including the promise of salvation through Jesus Christ.