suitableness

sopivuus puhekieltä The state or quality of being suitable, adapted or accommodated; suitability; fitness; propriety; agreeableness.
John Morley, Voltaire

Moreover, the modern argument in favour of the supernatural origin of the Christian religion, drawn from its suitableness to our needs and its divine response to our aspirations, must be admitted by every candid person resorting to it to be of exactly equal force in the mouth of a Mahometan or a fire-worshipper or an astrolater.