The word ' it' has many meanings: # l. the animal or thing previously mentioned or under discussion: neuter personal pronoun in the third person singular: ' it' is the nominative and objective form, ' its' the possessive, and ' itself' the reflexive and intensive; 'its' is the possessive pronominal adjective # it is also used as: 1. the subject of an impersonal verb without reference to agent: it is snowing 2. the grammatical subject of a clause of which the actual subject is another clause or phrase following: it is clear that he wants to go 3. an object of indefinite sense in certain idiomatic expressions [to lord it over someone]; often, specific, an unpleasant consequence: now you're in for it; let him have it 4. the antecedent of a relative pronoun from which it is separated by a predicate: it is your support that we want 5. a term of reference to something indefinite but understood, as the state of affairs: it's all right—I didn't hurt myself 6. Informal an emphatic predicate pronoun referring to the person, thing, situation, etc. which is considered ultimate, final, or perfect: zero hour is here: this is it In this case 'it' is the pronoun for the word 'sacrifice'