Forward and onward are synonyms. I’ve been pondering their meanings and applications. They do have distinctions.
When I think of the word onward, the image of marching soldiers comes to mind, perhaps a parade, perhaps Christian soldiers.
Onward implies motions like actors in a play. The director moves the play forward.
The word forward appears to be more anchored. Maybe this is because it reminds me of foreword, which comes at the front of a book.
Both onward and forward divide up space into partitions or wards.
Forward seems more psychological like the flow of ideas. It does not necessarily require the movement of weight.
Both imply movement towards a goal.
Working together they can move mountains.