Look at verse 4. Paul said they had not struggled against sin to the point of blood YET. Few in the church do. But some do. The thief on the cross was one of them. He was suffering horribly but he endured to the end and did not revile and mock Jesus despite his suffering. The other thief did not show any signs of an enduring faith. We know who was saved and who was not by this. We don't even wonder. But some in this thread would have it that we can't tell where saving faith resides by behavior.
The thief repented. And something about Jesus was understood by him. So his hope was placed in another, for he knew he deserved death. Maybe he heard the stories or saw the miracles? We don't really know. But, we do know that henplaced his faith in the only one who could help at that point. That's our salvation.
Am sure hes working in the kingdom now.