A Melbourne youth church leader who raped a 14-year-old girl, poured petrol on her and set her alight has been jailed for 21 years.

Michael Tuano Hermogenes, 25, plied the girl with alcohol before choking her with one of her stockings, raping her, taking photos of her while she was naked and unconscious, then setting her and her house alight to hide his crimes.

She suffered permanent injuries including burns to half her body, amputation of her right toes and spent almost a year in hospital.

Hermogenes pleaded guilty to charges including arson, attempted murder and rape over the attack at the girl's home in Melbourne's west in May last year.

He must serve 16 years before he is eligible for parole.