This is going to be one of my favorite prompts so far.
I use the Light as a sort of deity in my D&D games. It’s not a strict religion and is followed by Bards, Druids, and Clerics among others. It represents all things good, warm, benevolent, etc. It helps things grow, see at night, and so on. The Light is a good thing without being super specific and dogmatic. It also gives us a way to turn undead, cast spells, and heal.
A Light Based Magic Item for Fantasy RPGs.
Holy Symbol of Divine Light:
On Command: Sheds light as a torch.
On Command: Sheds light as a Continual Light Spell.
3x/day Detect Evil.
1x/day Detect Magic.
3x/day Lay on Hands (3 Dice) OR Cure Light Wounds as per the spell.
1x/day: Repels/Destroys Un-Dead as Level 5 Cleric or +3 to check and results if already Level 5.