Assuming you are correct in your interpretation of the word for world, that it applies only to sheep (which I disagree with), John was writing to first century Christians, not 21st century Christians. He was writing to the "world" and "the sheep" of his time.
If you are going to restrict this word "world" to your definition of "sheep," "elect," why not go right to the very context and restrict it to "first century believers" only. That is what the context is, isn't it?
Your definition is restrictive. You want to restrict it to the elect. You have redefined it to mean the elect only. Then keep on going. Take the entire context into view. It really means first century Christians only.
How, therefore, can you be sure that you are one of the elect?