Fallen in love with Christ, a young Muslim girl finds out that her existence depends upon her recognition of the truth – she’s in love with a non-existent person – her seek for truth only leads her to reveal her true nature – goodness and curiosity – questions asked and answered, her seek – immortality.

"A young girl looks to another faith, but immediately finds that her mortality may lie with a false deity."

While I think Foxtrot is on the right track, this attempt doesn't describe a plot. What's the inciting incident? What goal does that event cause the main character to pursue throughout the story? How does she go about achieving that goal?
Any logline for a film or television show should describe a visual action, something the producer can imagine on screen. Whether that's driving, shooting, fistfights, even praying. What causes her to believe in a false deity? How is that represented visually? What's the conflict that will be resolved at the climax of the story?

Eliminate the specific faiths for the purpose of the logline...

A young girl looks to another faith, but immediately finds that her mortality may lie with a false deity.

It also reads very clunky. I'd work on the flow to smooth en out the hook. Eliminate the names, Neero and Sara are unfamiliar to me, adjectives work better in loglines.