Bulmers Poster Advert

I'm seeing this poster all over London. But I find it weird. "In the beginning there was Bulmers"...

Bulmers poster

In the beginning of what?... Time? Party? Pubs? 

As much as I like drinking Bulmers (Pear flavoured one - as it's sweet) could someone please enlighten me what this phrase means! It feels like a mystery waiting to be resolved by the people of London...

Check out their new poster: http://asimplegeekylife.blogspot.co.uk/2012/10/bulmers-poster-advert-no2.html