John 1.1 ("In the beginning was the Word, and the Word was with God, and the Word was God") is the most obvious echo in the gospel of Genesis 1.1 ("In the beginning God created the heaven and the earth.")
However, there are other echoes, especially in chapters 7 and 8. But the most compelling one I see is in 8.25:
"Then said they unto him, Who art thou? And Jesus saith unto them, Even the same that I said unto you from the beginning."
"From the beginning," and "in the beginning" indicate eternity, especially the eternity of God. That Jesus describes Himself as having spoken something "from the beginning" is -- in Johannine writings -- a clear indication of divinity.