Where does "to keep fingers crossed" come from?

Question

When someone says they keep their fingers crossed, it means they wish or hope for a good outcome for someone or something.

Where does this idiom originate from? Why do people fold their one finger on another to hope for the best?

Answer 1

From the New Oxford American Dictionary:

cross one's fingers (or keep one's fingers crossed): put one finger across another as a sign of hoping for good luck. • hope that someone or something will be successful.

The origin of this hand gesture is discussed, for example, in Wikipedia. It is not fully clear, but probably comes from pre-Christian times, and thus does not have a relation to the Christian symbol of the cross.