Does a creature enchanted with Pacifism lose its abilities or just its ability to attack and block?

Classic Pacifism (the enchantment that reads "Enchanted creature can't attack or block") is a static ability that imposes two restrictions on the enchanted creature: it cannot be declared as an attacker and it cannot be declared as a blocker. That is the full extent of what Pacifism does.

The enchanted creature retains all of its other abilities — activated abilities, triggered abilities, static abilities, and keywords like flying or trample are completely unaffected. Under CR 701.4a, attacking is a specific game action declared in the declare-attackers step (CR 508), and blocking is declared in the declare-blockers step (CR 509.1). Pacifism prevents those declarations, nothing more.

Removing abilities entirely requires a different effect — something like "loses all abilities" or an effect that specifically overwrites the creature's text (see CR 702.2c for how ability-removing effects work). Pacifism contains no such language, so it does not strip abilities.

Concrete example: Your opponent's Prodigal Pyromancer ("T: deals 1 damage to any target") is enchanted with Pacifism. The Pyromancer cannot attack or block, but your opponent can still tap it to deal 1 damage to your creature or planeswalker — its activated ability is completely intact.

So: Pacifism only restricts attacking and blocking (CR 508.1, 509.1). All other abilities of the enchanted creature remain fully functional.