The Gospels indicate that Jesus’ full humanity as David’s heir, and full divinity as the ruler of the universe, relate closely to his role as Christ and to the “good news” or “gospel” he announced.
After Jesus’ Farewell Discourse and final prayer, Jesus was arrested. But even though He knew He was going to be crucified, Jesus made no effort to avoid arrest. He allowed himself to be taken, beaten, and executed.
We have canonical evidence. We have extra-canonical evidence. We have evidence from Josephus. We have evidence from other early Christian sources that are not in the New Testament. We have evidence from the Roman historian Tacitus. We have evidence from Suetonius, and other roman historians, so we have both biblical and extra biblical evidence that Jesus existed. In addition to that, we have epigraphic evidence; we have archeological evidence.
“The time is fulfilled, and the kingdom of God is at hand. Repent and believe the gospel.” The gospel is the good news proclaiming that the reign of God’s kingdom has come into this world.
When Christians become disciples, become sons of God in that sense there is, of course, a kind of transformation, a kind of likeness with God that happens to us, but that of course is true with Christ in His capacity as Son in ways that go far beyond what any disciple of Christ can claim.
The divinity of Christ says, because He is Lord, because He is God, what He says about himself and about who we are and what the way of salvation is, is authoritative and final. Christianity is definitely Jesus. Without Jesus it would not exist.
He gives us the strength to say “no” to sin, and so, “yes” to God — say “yes” to God — and to say “yes” to obedience. And only God can do that. The Holy Spirit is God, and he does those mighty works in our lives and in our world. He rules over every event. He saves us, literally. He brings salvation that Jesus Christ earned into our lives and makes it ours. And He continues to change us until we meet Jesus someday.