23Then he said to them all: "If anyone would come after me, he must deny himself and take up his cross daily and follow me. 24For whoever wants to save his life will lose it, but whoever loses his life for me will save it 25What good is it for a man to gain the whole world, and yet lose or forfeit his very self? 26If anyone is ashamed of me and my words, the Son of Man will be ashamed of him when he comes in his glory and in the glory of the Father and of the holy angels (Luke 9:23-26).
In the year 771, Charlemagne became king of the Franks, a Germanic tribe in present-day Belgium, France, Luxembourg, the Netherlands, and western Germany. He had gained an empire, but yet in his dying days, he had found out the truth that to live for oneself and to obtain an empire without Christ seated on the throne of one’s life was to die a miserable death. One hundred and eighty years after the death of Charlemagne, about the year 1000, officials of Emperor Otho opened the great king’s tomb where, in addition to incredible treasures, they saw an unusual sight: the skeletal remains of King Charlemagne seated on a throne, his crown still on his skull, and a copy of the Gospels lying in his lap with his bony finger resting on the text, “What good is it for a man to gain the whole world, yet forfeit his soul?”
Too many people rush about seeking fame and fortune, desperately putting all their time, energy, and money into climbing the ladder of success, only to find at the end of their lives that their ladder has been against the wrong wall. Life is too short to have regrets about how you have spent your years in frivolous things. Jesus said, that if we want to follow Him, to be His disciple, there are three things we must do: deny ourselves, take up a life of cross-bearing, and do it daily.
Some feel that to deny oneself would be not to do anything pleasurable, not ever to eat chocolate, or see a movie. To deny oneself, in their opinion, means to do nothing that would be fun. However, Jesus said, “The thief comes only to steal and kill and destroy; I have come that they may have life, and have it to the full” (John 10:10). If to follow Jesus means never to enjoy life or never to have fun, it sure doesn’t sound like it would be a life of living to the full. So what does it mean?
1) To deny ourselves. I believe that this means that pleasing our Lord is to be a higher priority than that of pleasing self. We must put His will first and foremost in our lives. If we can imagine a throne room in the temple of our hearts (1 Corinthians 3:16), Christ needs to sit there, and not ourselves. He must rule and reign. The Greek word translated as deny means not only to say no to something but also it is used to refuse someone. William Barclay, the Bible commentator, further defines it, saying:
"Ordinarily, we use the word self-denial in a restricted sense. We use it to mean doing without something, giving up something. For instance, a week of self-denial is a week when we do without certain pleasures or luxuries, usually to contribute to some good cause. But that is only a tiny part of what Jesus meant by self-denial. To deny oneself means that in every moment of life to say no to self, and to say yes to God. To deny oneself means to obliterate self as the dominant principle of life, and to make God the ruling passion of life. A life of constant self-denial is the life of continual saying yes to God." 
2) You and I, as disciples, need to take up our cross daily. A cross was an implement of death. When a man was seen carrying a cross, people knew he was on his way to death. A life of purpose (a life of dedication to Christ), i.e., real life, comes to us when we dethrone self and place Christ as the central focus of our lives. This life that we have on Earth is but a seed to be sown into the lives of others. Selfishness is gone when we have an attitude of heart that puts the needs of others before oneself. Paul the Apostle was an excellent example for all of us in his words: “I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me” (Galatians 2:20). To be crucified with Christ is to live for the purpose of doing God's will daily, even when our flesh life craves the opposite. This is a Spirit-controlled life.
3) We are to follow Christ. Many seem to follow the way of self. They bow at the shrine of I, Me, Mine, Myself. To the follower of Christ, his heart is to be like Jesus in every way that He lived His life. We are to follow His example. He modeled to us how we are to live. Christ Jesus has bought us, not with silver or gold, but with the most valuable thing that He had: His blood, His life in this world. Jim Elliot, one of five missionaries who died seeking to reach the Auca Indians of South America with the message of Christ, said this: “He is no fool who gives what he cannot keep to gain what he cannot lose” (Shadow of the Almighty, Zondervan, Grand Rapids, Page 15).
These notes are taken from the in-depth Bible study series on Luke. Click the following link: Peter's Confession Keith Thomas
 R. Kent Hughes, Preaching the Word, Luke Volume One, Printed by Crossway Books, 1998. Page 342.  William Barclay. The Gospel of Matthew, Vol. 2. The Daily Study Bible Series (Philadelphia, Pa.: Westminster Press, 1958) p. 167.