'Only Son' in the Bible

And as he approached the gate of the town, behold, a man who had died was being carried out, his mother's only son, and she was a widow. And a large crowd from the town was with her.

For in this way God loved the world, so that he gave his one and only Son, in order that everyone who believes in him will not perish, but will have eternal life.

The one who believes in him is not judged, but the one who does not believe has already been judged, because he has not believed in the name of the one and only Son of God.

By this the love of God is revealed in us: that God sent his one and only Son into the world in order that we may live through him.