How do we know that God's word through Samuel was true?

The certainty of God's word is rooted in His faithfulness and the fulfillment of prophecy. In 1 Samuel 4, the prophecies spoken through Samuel about Eli's family came to fruition when the Israelites faced defeat in battle. Every prophecy from God is a revelation of His sovereign will, and its fulfillment serves as a testament to His truthfulness. Moreover, as it states in 1 Thessalonians 5:24, 'He who calls you is faithful; he will surely do it.' This emphasizes that God's promises and warnings should be heeded, as they will come to pass.