"For he who is least among you all--he is the greatest." (Luke 9:48)
When Christ said that, "Whoever finds his life will lose it, and whoever loses his life for my sake will find it," in
Matthew 10:39, he showed the incredible extremity of following Christ.
When you die, or lose your life, your entire life is involved. So when Jesus tells us that we have to lose our life in order to have eternal life, he is not talking about losing just one aspect of your life. No, he is talking about losing your entire life. Everything.
What does this translate to our lives now? It means full and complete submission to Christ's will regardless of the consequences. Every sinful aspect of our life needs to be completely destroyed and never touched again in obedience to Christ.
We are to give everything in our life, and even our life itself for God's use, not our own.