How do we know that John's testimony about Jesus is true?

The truth of John's testimony can be seen in John 10:41-42, where the people acknowledged, 'John did no miracle, but all things that John spake of this man were true.' John's role as a witness was divinely appointed, emphasizing the reliability of his proclamation. His declaration 'Behold the Lamb of God' underscores the centrality of Christ in salvation. This aligns with the Reformed understanding that saving faith is predicated upon the revealed truth of God through the Scriptures, and the conviction that John's message has been preserved and affirmed throughout the history of the Church.