For whoever wishes to save his life [in this world] will [eventually] lose it [through death], but whoever loses his life [in this world] for My sake will find it [that is, life with Me for all eternity].
True life is found in Jesus Christ. If we choose to follow Jesus Christ we must be willing to lay down our lives for Jesus and His kingdom. This means that we lay down our selfish desires and our own will, and the driving force in our lives becomes the will of God.
This is contradictory to the world that we live in. The world tells us that only contentment and happiness is found in seeking after every selfish desire. But seeking after our selfish desires only leads to destruction. If we desire to experience the abundant life that Jesus speaks us requires that we lay down our lives. There will be pain and suffering, but through it all the Lord’s grace is sufficient and He will strengthen us for all that we will face.