The text does not explicitly state that 'world' means 'elect' or 'believers'. John chose to use 'kosmos' for a reason.
1In the beginning was the Word, and the Word was with God, and the Word was God. 2He was with God in the beginning. 3Through him all things were made; without him nothing was made that has been made. 4In him was life, and that life was the light of all mankind. 5The light shines in the darkness, and the darkness has not overcomea it.
6There was a man sent from God whose name was John. 7He came as a witness to testify concerning that light, so that through him all might believe. 8He himself was not the light; he came only as a witness to the light.
9The true light that gives light to everyone was coming into the world.
'World' here means 'creation' in general, but specifically to all humanity on earth.
10He was in the world, and though the world was made through him, the world did not recognize him.
Meanings: created world, created world, humanity.
11He came to that which was his own, but his own did not receive him. 12Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God 13children born not of natural descent, nor of human decision or a husbands will, but born of God.
14The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who came from the Father, full of grace and truth.
15(John testified concerning him. He cried out, saying, This is the one I spoke about when I said, He who comes after me has surpassed me because he was before me.) 16Out of his fullness we have all received grace in place of grace already given. 17For the law was given through Moses; grace and truth came through Jesus Christ. 18No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known.
19Now this was Johns testimony when the Jewish leadersc in Jerusalem sent priests and Levites to ask him who he was. 20He did not fail to confess, but confessed freely, I am not the Messiah.
21They asked him, Then who are you? Are you Elijah?
He said, I am not.
Are you the Prophet?
He answered, No.
22Finally they said, Who are you? Give us an answer to take back to those who sent us. What do you say about yourself?
23John replied in the words of Isaiah the prophet, I am the voice of one calling in the wilderness, Make straight the way for the Lord.
24Now the Pharisees who had been sent 25questioned him, Why then do you baptize if you are not the Messiah, nor Elijah, nor the Prophet?
26I baptize withe water, John replied, but among you stands one you do not know. 27He is the one who comes after me, the straps of whose sandals I am not worthy to untie.
28This all happened at Bethany on the other side of the Jordan, where John was baptizing.
29The next day John saw Jesus coming toward him and said, Look, the Lamb of God, who takes away the sin of the world!
In view of the definitions of 'world' thus far, I cannot see why we should necessarily suddenly infer that John means 'elect'.
B. F. Westcott
"The fundamental idea of kosmos in St. John is that of the sum of created being which belongs to the sphere of human life as an ordered whole, considered apart from God....the world comes to represent humanity in its fallen state, alienated from its Maker."
John Calvin says of this verse: "He uses the word sin in the singular number for any kind of iniquity; as if he had said that every kind of unrighteousness which alienates men from God is taken away by Christ. And when he says the sin of the world, he extends this favor indiscriminately to the whole human race."
Ryle similarly states: "Christ is...a Savior for all mankind....He did not suffer for a few persons only, but for all mankind....What Christ took away, and bore on the cross, was not the sin of certain people only, but the whole accumulated mass of all the sins of all the children of Adam....I hold as strongly as anyone that Christ's death is profitable to none but the elect who believe in His Name. But I dare not limit and pare down such expressions as the one before us....I dare not confine the intention of redemption to the saints alone. Christ is for every man....The atonement was made for all the world, though it is applied and enjoyed by none but believers."