What does Luke 9:25 mean?

The disciples thought they had the whole world in front of them. Their rabbi is the Jewish Messiah. The purpose of their version of Messiah is to restore the nation and drive out its enemies. He is expected to bring peace, prosperity, and the respect of other kingdoms. As the Messiah's closest followers, the disciples would rule with Him. They think they are following the lesson of this verse. Later, Luke will describe three interactions Jesus has with potential disciples (Luke 9:57–62). He tells them what it will cost. The Twelve have already agreed to live an itinerant lifestyle and abandoned comfort and even family obligations for a while.

Jesus is telling them that sacrifices are the beginning; following Him requires more. They must publicly affirm Him and His message to the point of crucifixion (Luke 9:23).

Matthew and Mark put a finer point on the situation. Those who reject Jesus risk losing their souls (the same Greek word Luke used in the previous verse translated as "life"): not just their bodies or reputation or earthly accolades, but their entire being. There is nothing a person can gain in this world that is worth losing his or her soul (Matthew 16:26; Mark 8:37–38). Better to have a dead body—which was going to die someday, anyway—than suffer separation from God for eternity. We may postpone the deaths of our bodies for a time, but only submitting ourselves to Christ fully will ensure real life: "You keep him in perfect peace whose mind is stayed on you, because he trusts in you" (Isaiah 26:3).

As do teachers in every era, messengers in the Bible, including Jesus, use "rhetorical" questions. The intended meaning is a statement, even if it's phrased as a question. This statement is clear: "It profits a man nothing if he gains the whole world and loses or forfeits himself." Jim Elliot said it this way: "He is no fool who gives what he cannot keep to gain what he cannot lose."