In the Book of Revelation, Jesus says the following:
14"To the angel of the church in Laodicea write:
These are the words of the Amen, the faithful and true witness, the ruler of God's creation. 15I know your deeds, that you are neither cold nor hot. I wish you were either one or the other! 16So, because you are lukewarm—neither hot nor cold—I am about to spit you out of my mouth." (Rev. 3:14-16)
One of the interpretations of this passage that I have oftened heard preached is that people who are lukewarm are resistant to repentance. It is easier for a Christian who is hot to repent and for a Christian who is cold to repent than it is for a Christian who is lukewarm (Jesus is speaking to a church so this is in the context of actual believers).
My point here is that we all need to live a life of repentance, or change, under the direction of the Holy Spirit. Many people think of repentance as something we need to do if we have been "bad" or disobedient (and repentance is certainly useful in those situations :). But our relationship with God should be such that; as we experience worship, prayer, meditation, Bible reading, service; as we minister to others, encourage others, and help others; one result of those experiences is that we think a little differently. That those experiences result in repentance.