We know God will fulfill His promises through His unchanging nature and previously fulfilled prophecies as seen in Scripture.
God's faithfulness is rooted in His character; He is unchanging and sovereign. Throughout Scriptures, God has made numerous promises that He has consistently fulfilled. For instance, in Genesis 15:12-14, God tells Abraham that his descendants will be afflicted for four hundred years, which later came to pass in the Exodus. This history provides evidence that God will certainly fulfill His future promises, including the promise of eternal life to those who believe in Christ. Our assurance is derived from understanding that faith is not only believing that God can do what He says but also trusting that He will do it.
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