The act of believing in something, despite lack of proof of its truth or existence
If you take a leap of faith, you do something even though you are not sure it is right or will succeed. Take a leap of faith and trust them
A leap of faith, in its most commonly used meaning, is the act of believing in or accepting something intangible or unprovable, or without empirical evidence. It is an act commonly associated with religious belief as many religions consider faith to be an essential element of piety, as well as scientists who take a great leap of faith when a new Idea is thought of, as well as the believing in the unprovable and the theoretical