Synonyms for Motivating:

adj.

all (adjective)
motive, motivative.

n.

act (noun)
motivation.
motivating (noun)
motivative, motivation, motive, causative.

v.

aiding (verb)
funding, Abetting, attending, Facilitating, fostering, Endowing, Aiding, ministering, encouraging, Relieving, Sustaining, tending, Mothering, Assisting, supporting, serving, benefiting, helping.
causing (verb)
Engendering, inspiring, acting, Enforcing, provoking, Generating, engineering, inducing, driving, bringing about, Producing, executing, Effecting, giving rise to, Eliciting, Originating, Forcing, causing, Evoking, making.
compelling (verb)
sparking, Fomenting, impelling, hijacking, galvanizing, nagging, intimidating, Bulldozing, mandating, bullying, pushing, pressing, Dragooning, urging, propelling, obliging, Coercing, compelling, goading, daunting, stimulating, Inciting, Dictating, stressing, Browbeating.
influencing (verb)
Prejudicing, commanding, Biasing, swaying, leading, affecting, mastering, controlling, Predominating, Authorizing, Influencing, pressuring, Empowering, powering.
motivating (verb)
hurling, enticing, fermenting, knocking, Ramming, prompting, triggering, launching, prodding, shooting, Magnetizing, catapulting, hastening, poking, moving, heaving, hurtling, striking, slinging, jogging, pitching, Nudging, jostling, Lobbing, Shoving, Bumping, Throwing, Flinging, Punching, thrusting, firing, Instigating, energizing, jerking, jolting.

Other synonyms:

Other relevant words:
motivative, motivation, motive, causative.