It’s The Boat
Imagine a ship filled with people crossing the Atlantic. In the middle of the ocean there is an explosion. The ship is severely damaged and slowly sinking. Most are dead, and the rest are rushing for the lifeboats.
Now suppose one man doesn’t know about the lifeboat, so he does not get aboard. He doesn’t have knowledge, so he is not saved.
Suppose another man knows about the lifeboat and believes it will save his life, but he is grief-stricken over seeing his wife killed, so he chooses not to get aboard and dies with his wife. He has knowledge and mental assent, but he is not saved.
Others believe the lifeboat will save them, and they get into the boat. They are saved by faith, that is they have knowledge, mental assent, and trust. However, it is not their faith that saves them--no matter how much they have. It is the boat.
Saving faith trusts Christ, and Christ saves. (Evangelism, A Biblical Approach, M. Cocoris, Moody, 1984, p. 77)