Bless is an Enchantment Spell found in Baldur's Gate 3.
Class and Race Restrictions
Bless can only be used by the following classes / subclasses:
- Bard (College of Lore Level 6 Magical Secrets, or Level 10 Magical Secrets)
- Cleric (can be used by all Clerics, but Life Domain always have the spell prepared)
- Paladin
You can also learn this Spell by selecting the following Feats:
- Magic Initiate: Cleric
Characters that equip the 
Staff Of Arcane Blessing can use this spell once per long rest.
If you purchase a statue of a character from Boney in the Circus of the Last Days, that character can gain a similar effect (named Sweet Stone Features) permanently.
If wearing 
The Whispering Promise ring, any creature a character heals also gains the benefits of Bless for 2 turns.