What is Religion?

Presently I am listening to a podcast from the CBC Radio program Tapestry. Jonathan Sacks, the former Chief Rabbi of the United Kingdom is being interviewed. Quite apart from the fact he is a highly intelligent and thoroughly decent man and of course a very religious man was his definition of religion. The interviewer said she had a friend who no longer practiced the religion she was raised in, but felt a need to find one she could believe. Jonathan Sacks's reply was that in Judaism religion is not a set of beliefs. The word 'faith' in Hebrew, he said, is better translated as 'being faithful', rather than by the word 'faith'. He goes on to say further, that 'religion' for Jews is not a body of knowledge that could, for example, compete with science.  Religion, he said, is not a set of beliefs, rather it is a set of relationships.