Who first said this Quotation?
I think it predates 1990.
A few years back, I asked on Y!A who originally said this, and one respondent said they believed they'd heard it in a movie based around swimming, but couldn't recall which movie.
I personally thought it may have been a clergyman of some sort, like a priest or rabbi, and they may have said it on a religious show on TV or Radio, like Radio 4's "Thought for the Day", or ITV's "Late Call".
I've tried Web searches, all manner of websites I've come across, books on quotations, and even Nigel Rees' Radio 4 show "Quote, Unquote", and have never found the answer.