“Put your trust in God and keep your powder dry.” A quote that was first seen at the poem “Oliver’s advice” by William Blacker in 1834 and was used by Oliver Cromwell (English military and political leader) during his campaign in Ireland (1649 – 1653). The general meaning of the phrase was “Trust in God, be prepared and keep your supplies for the right moment” or “Trust in God and wait for the right moment to take your decision”. The phrase was literally referring to the powder that the soldiers had to keep dry in order to be ready to fight.
The quote was used a lot in the US during WWII.