expression
faith can make anything seem sacred; faith is mysterious
Proverb meaning that if you believe strongly enough, even something worthless like a sardine's head can become an object of reverence. Often used to comment on the power of belief or the irrationality of faith.
鰯の頭も信心からで、彼はその石ころをお守りだと言って大切にしている。
Faith can make anything seem sacred; he treasures that pebble, calling it a lucky charm.
あの人があんな変な宗教を信じているのは、鰯の頭も信心からというやつだね。
The fact that he believes in such a weird religion just goes to show that faith is mysterious.
A traditional Japanese proverb. The literal meaning is 'even a sardine's head (can become an object of worship) through faith'. The exact origin is uncertain, but it reflects a common folk observation about the power of belief.