Christians follow their Lord by imitating his life & obeying his commands. To take up the cross means to obey selfish desires to use our resources of time & money our own way, & to choose our own direction in life. Following Christ is costly now, but in the long run it is well worth the pain & effort.
Nothing material can compensate for the loss of eternal life. Jesus' disciples are not to use their lives on earth for their own pleasure, but to spend them serving God & people.
Luke's Greek audience would have found it difficult to understand a God who could die, just as Jesus' Jewish audience would have been perplexed by a Messiah who would let himself be captured. Both would be ashamed of Jesus if they did not look past his death to his glorious resurrection & Second Coming. Then they would see him not as a loser but as the Lord of the universe who through his death brought salvation to all people.
When Jesus said some would not die without seeing the Kingdom, he was referring to (1) Peter, James, & John, who would witness the transfiguration eight days later, or in a broader sense to (2) all who would witness the resurrection & ascension, or (3) all who would take part in the spread of the church after Pentecost. Jesus listeners were not going to have to wait for another, future Messiah - the Kingdom was among them, & it would soon come in power.
What does Jesus want from us? Total dedication, not half-hearted commitment. We can't pick pick & choose among Jesus' ideas & follow him selectively; we have to accept the cross along with the crown, judgment as well as mercy. We must count the cost & be willing to abandon everything else that has given us security. With our focus on Jesus, we should allow allow nothing to distract us from the manner of living he calls good & true.
Reference summary used from the Life Application KJV Bible, Tyndale House Publishers, Inc., Wheaton, Illinois