What does Einstein’s metaphor about science and religion mean?

Albert Einstein’s full quote:

“Science  can  only  be  created by  those  who  are  thoroughly imbued  with  the  aspiration towards truth and understanding. This source of feeling, however, springs from religion. To this there also belongs the faith in the possibility that  the regulations valid for the world of existence  are  rational, that  is,  comprehensible  to  reason. I  cannot  imagine a scientist without that profound faith. The  situation  may be  expressed by an image: science without religion is lame, religion without science is blind.”