'Only begotten' in the Bible

And the Word was made flesh, and dwelt among us, being full of grace and truth: and we beheld his glory, the glory as of the only-begotten of the Father.

and though no one hath ever seen God, or can see Him: yet the only-begotten Son, who is in the bosom of the Father, hath made Him known.

For God so loved the world, that He gave his only begotten Son, that whosoever believeth on Him might not perish, but have everlasting life:

He that believeth on Him is not condemned: but he that believeth not, is already condemned; because he hath not believed on the name of the only-begotten Son of God.