Sentence:  In fact , He came into this world Himself , in the person of His Son , Jesus Christ , who stood here amid the darkness of human sin and said : `` I <WSD>am</WSD> the light of the world : he that followeth me shall not walk in darkness , but shall have the light of life '' . 
Meaning of the word marked with <WSD> tags:  be identical to; be someone or something