Why is it required for a convert to live in a Jewish community before their formal conversion?

Judaism isn’t a question of belief like other monotheistic religions (“believe and you will be saved”) but it is a religion of actions. A 13th-century explanation of the 613 commandments Judaism claims are woven through the Biblical narrative opens with the statement: The hearts follow the actions. i.e. by acting in a certain fashion, ultimately if you are acting that way because you (have been taught to) believe that it is the moral or ethical way to behave — ultimately it will influence your beliefs and opinions.

It is therefore very difficult to learn actions from a book! As a convert to Judaism almost 50 years ago I can testify that many of the problems that both converts and Jews who returned to their tradition in their adulthood face, often stem from their lack of informal day-to-day exposure to the minute of life as an observant Jew within a Jewish family — something you cannot learn from a book.

To ensure that candidates for conversion ** understand what they are committing themselves to — they need to experience the life they purport to want to embrace. Only then can they sincerely declare they understand what they are adopting.

More philosophically I’ve come to believe that to fully *understand* Judaism you must *experience* it. In that sense, Judaism is very existential or perhaps “experiential”. Over the years I’ve counseled several young men on what to expect from marriage. After a few years, I realized that I needed to add a preamble to these sessions. I’d explain that I would answer all their questions but warned them that, although they might understand my answers intellectually, the reality is that until they found themselves face-to-face with their bride in the situations we discussed, they would not understand. Only then, in the crux of the moment would they be able to look back and say to themselves “Oh! That’s what he meant!” Intellectual understanding does not equal the visceral immediate internalization that living it entails.

[Originally published as a reply to a question on Quora.com]