The first and last message that Jesus preached to israel was one of repentance.
Understanding the change, being willing to change and actually changing is repentance.
The KingdomOfHeaven is the HolySpirit who issues from the SpiritRealm into the PhysicalRealm.
Jesus is Immanuel - God with us.
The HolySpirit is God in us.
Repentance is changing from a hopeless CarnalMinded state of existence to EternalLife and AbundantLife by virtue of being One with the HolySpirit of Christ Jesus.