Please can anyone offer advice?

I need to VISUALLY divide/split my A4 page into 4 EQUAL quadrants. I only need to SEE the 4 quadrants whilst I am working and designing. They must not show up when I finally print or cut the design.

To explain my purpose - I want to work with an A4 page (physically), but the intention is to design two A5 cards at once, so that I can cut and or print on a single A4 page once I am finished designing.