The Rich Man, the Impossible Kingdom, and Treasure in Heaven
A man runs to Jesus asking what he must do to inherit eternal life. Jesus recalls commandments concerning human relationships, then looks at the man with love and identifies the one thing holding him: sell what he has, give to the poor, gain treasure in heaven, and follow. The man leaves grieving because he has great possessions. Jesus compares the difficulty of the rich entering the kingdom to a camel going through the eye of a needle.
Where this fits in the story: wealth can appear to signal blessing and security, but Jesus exposes its power to possess the possessor. The disciples ask who can be saved, and Jesus locates hope where Mark consistently locates it: what is impossible with people is possible with God.