How do we know that Jesus is truly sent by God?

In John 7:16-18, Jesus asserts that His doctrine is not His own but belongs to the Father who sent Him. This declaration is significant as it underscores the complete harmony between the Son and the Father. Jesus teaches that a messenger from God will lift up God's glory rather than their own, confirming their divine appointment. Thus, any true proclamation of the gospel will resonate with the message of God's grace, and glorify Christ as the sole Savior, ensuring that it is authentic and divinely sanctioned.