Repentance is definitely a result of a new heart in the believer. It's a free gift from God, even though its a gift I'm still responsible. If God had never granted it to me it would never of happened. And whats more amazing about this is that those who repent are in the one body, the one church - Jews and gentiles alike all in Christ.
--- and saying, “The time is fulfilled, and the kingdom of God is at hand. Repent, and believe in the gospel.” (Mark 1:15)
--- Jesus answered him, “Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God.” (John 3:3)
And just to show this is one message, one gospel for all here is Paul He taught the same things as Jesus.
---- They arranged to meet Paul on a certain day, and came in even larger numbers to the place where he was staying. He witnessed to them from morning till evening, explaining about the kingdom of God, and from the Law of Moses and from the Prophets he tried to persuade them about Jesus.
---- “Now I know that none of you among whom I have gone about preaching the kingdom will ever see me again.