Repent, for the kingdom of heaven has come near. Matthew 3:2 and Matthew 4:17

Each verse referenced above records the same statement made by two different individuals. Who were they?

What did John the Baptist mean when he claimed that the Kingdom of Heaven was near?

What did Jesus mean when he claimed that the Kingdom of Heaven was near?

Why did both mean say that the arrival of the Kingdom of Heaven called for repentance? How does this truth inform our celebration of Advent as a penitential season?

How do you know that the Kingdom of Heaven has come near?