* Shine forever! (imperative sentence) => 영원히 빛나라 / 영원토록 빛나라 / 영원히 빛나세요 (polite form).
* to shine forever (infinitive form) => 영원히 빛나다.
There are these synonyms related to 빛나다.
* 빛나다(vi) = to shine (glow or sparkle creating a distinctive light source) or to illuminate.
* 비추다(vt) = to illuminate (radiate light on something).
* 비치다(vi) = to show (a light or shape become visible) or to illuminate (passive verb of 비추다).