I am not sure this exists, but I will Ask anyway. For their honeymoon my son and his wife would like to go to an amazing all inclusive resort with a beautiful swimmable beach and great food. In Europe. Help please.

When will their honeymoon be? How long will they have? How large is their budget? (I suspect if there is such a thing - not sure - the budget will be very high.)

Honestly, if they don't really want to experience anything much of Europe at this time (and very understandable if they just want to hang out and relax), and they want an all exclusive with a great beach, why not just do someplace in the Caribbbean and save a bundle on airfare.
OTOH, if Europe is calling them, have a look at Spain and Turkey.

Precisely what all Club Meds offer (not to mention their clones like Club Robinson).

All over the Mediterranean: just go to their site.

Greece has plenty of all inclusive hotels, go to
www.booking.com and have a look at hotels in Crete and Rhodes.

This place used to get great reviews, but I think less so recently - try tripadvisor... it is marketed as a very exclusive family resort but there is a section for honeymooners on the website - it gets lots of celebrity guests so should be pretty high end...

http://www.fortevillageresort.com/