sum, effect, substance, inwardness, essence, kernel, heart, center, burden, nitty-gritty, more...

nitty-gritty, details, specifics

main idea, theme, moral, purpose, message, more...

whole, general, real, very, main, basic, true, overall, radiant, full, essential

the main point,   the meat of,   basic point,   the jist,   main details,   some points,   the big details