These days most brides and grooms are paying for their own weddings and would like their invitation to come from them.  Our most popular wording for this is something like

Lynn & Matthew (in script font)

together with their families (optional)

would like to invite you

Guest Name

to help them celebrate their marriage (or wedding)

On date

at (Ceremony details)

with a reception to follow at (reception details)

RSVP details and dress code

Hope this helps

Lynn