Several years ago I saw a television episode of Hangin' With Mr Cooper, where one of his students turned out to be a child prodigy at the piano. This student could immediately reproduce anything he heard on the piano, hitting all of the right notes with the right dynamics. But this student was so focused on playing the right notes that he played with "no soul." Eventually, Mr Cooper called in somebody who couldn't play as well as this prodigy but who knew how to play with heart and emotion to teach this young prodigy the difference between playing with great technical skill and playing with soul.
When Jesus appeared to the Apostle John during his exile to the Island of Patmos, he asked John to write a letter to the church in Ephesus because the local church there had a very similar problem to Mr Cooper's piano prodigy. Jesus told that church, I know your works, your labor, and your endurance, and that you cannot tolerate evil. You have tested those who call themselves apostles and are not, and you have found them to be liars. You also possess endurance and have tolerated many things because of My name and have not grown weary. But I have this against you: You have abandoned the love you had at first (Revelation 2:2-4, HCSB).
The church in Ephesus was doing all of the right things. They were working hard, their lives were characterized by righteous living and discernment, they ensured hardship and refused to give up or give in. They were hitting all of the right notes, but they were living the Christian life with no soul. There wasn't any heart or love in what they were doing. They lived the Christian life well because they had practiced it so long, but not because they were still in love with Jesus.
Jesus' solution for this church, oddly, was to go back and do the things they did at first in their walk with God. Likely, he didn't mean to go back and act as immaturely as in that initial phase of the Christian life, but to go back and work through things the same way they had to in the beginning - to examine themselves against Jesus' teachings, to study it like they aren't familiar with it, to embrace the struggle against sin and pursue God with their whole hearts because they had realized how much God loves them. We, too, have to intentionally submit ourselves to the corrective guidance of the Holy Spirit and remember why we do all that we do in the Christian life.
Jesus doesn't want us to follow a checklist of good, Christian behaviors because we've gotten so good at it. He wants us to love Him with all of our heart, soul, mind and strength, not to just go through the motions we have practiced so long.