Your argument about metanoia and the Gospel of John overlooks crucial historical context. John's Gospel was written last, around 90-100 CE, and reflects later theological developments rather than Jesus's earliest teachings. The earlier Synoptic Gospels consistently show Jesus calling for both changed minds (metanoia) and changed lives.

The claim that Jesus "hardly ever said change or 'repent'" is incorrect. In Mark, our earliest gospel, Jesus's first public words are "The time is fulfilled, and the kingdom of God has come near; repent, and believe in the good news" (Mark 1:15). Matthew and Luke record similar teachings.

The Greek word metanoia does indeed mean a change of mind, but in Jesus's Jewish context this inherently meant a change in behavior. First-century Judaism didn't separate belief from practice - they were inseparable. When Jesus told people to "repent," he wasn't just asking them to believe different things, but to live differently - to reorient their entire lives toward God's kingdom.

This is evident in Jesus's teachings throughout the Synoptics:

- He tells the rich young ruler to sell his possessions and give to the poor

- He teaches that we will be judged by how we treat the hungry, thirsty, and imprisoned

- He says "Not everyone who says to me 'Lord, Lord' will enter the kingdom of heaven, but only the one who does the will of my Father"

Regarding Paul - the historical record clearly shows tensions between him and the Jerusalem church. Paul himself describes this conflict in Galatians 2. The Jerusalem Council in Acts 15 further demonstrates these early disagreements over what following Jesus meant. Further, Paul almost never mentions the kingdom, despite it being so central to Jesus's message.

You're right that Jesus preached the kingdom of God - but he preached it as a present reality that people could participate in through changed lives, not just changed beliefs. Reducing his message to just "believe" misses the radical way he called people to live.