Accepting responsibility for your sin is vital.
Passing the buck is an expression said to have originated from poker. A marker or counter (e.g., a knife with a buckhorn handle during the American Frontier era) was used to indicate the person whose turn it was to deal. If the player did not wish to deal he could pass the responsibility by passing the 'buck', as the counter came to be called, to the next player.
'The buck stops here' is a phrase that was popularized by U.S. President Harry S. Truman, who kept a sign with that phrase on his desk in the Oval Office. The phrase refers to the fact that the President has to make the decisions and accept the ultimate responsibility for those decisions. Truman received the sign as a gift from a prison warden who was also an avid poker player.