i disagree. to prove something exists is to destroy the nature of faith. true faith is trust. trust that is based on evidence without proof. you feel that something is true, because evidence has led you to believe it despite your questioning of it. you cannot find the final puzzle piece, but you trust that because of the evidence, you believe that this something is true. that is faith. it is not specific to whatever religion anyone follows.
with certain proof faith is unnecessary as it is simply replaced by unquestionable fact. therefore i argue that the problem with spirituality these days is not a lack of evidence, but a lack of faith and healthy questioning. people don't question what they are told enough, they don't seek the answers, and if they find evidence for something without proof, and that evidence is compelling enough, they lack the faith to trust in it. scientific proof destroys faith and thus also destroys spirituality. the nature of spirituality is closely associated with that of the spirit, a vastly unscientific entity.