Today we hear in the Gospel "take up your cross." Many think this means bearing burdens and suffering hardships for the Lord. Surely such hardships will at times be required, but there is a fuller meaning if we consider the context.
What is a cross for? It was not just a burden to be borne. Far more than that, it was an instrument of death and total sacrifice. Jesus said take up our cross and follow Him. He bore a cross and we must bear our cross and follow Him. But where was He going with His cross? He had just said He was going to die. In the next verse Jesus said we must give our lives for Him. Then He asked what good our lives would be to us, if we are unacceptable at the judgment.
Hence, "taking up your cross" refers to giving your whole life to God, as Jesus was about to give His life for us. This involves bearing burdens, but it is deeper than that. It is a total dedication of life. Our whole life is given to His service in anything He says. This will lead us to willingly deny self. Following Him then requires us to live as He lived His life.
The determination to give our lives to God's service is called "repentance." In repenting we determine to turn away from our own will and live our lives to please God. We cannot be saved without this, and that is why repentance is so important in salvation.
The next verse then helps us understand Jesus' point and strengthens the application. If a person holds his life so dear to himself that he wants to use it to please himself, do his own will, and accomplish his own purposes, rather than denying self and serving God, that person will in the end loses his life eternally. But anyone who loses his life for Jesus' sake - gives it in service and sacrifice to God by denying himself, as described above - such a man will save his life by gaining eternal life.
There can be no greater or clearer teaching anywhere of the meaning of being a disciple. This is how our Master lived, so this is how His disciples must live. We must live lives of complete and total submission to the will of God.