Jesus of Nazereth used this term to illustrate what he meant by sonship.

Had he wanted to let folks know that he was the child of a woman (Mary) then why didn’t he say "Son of Woman?" It would have fit perfectly with the prophecy in Genesis (see Genesis 3:15). And, if he was actually making some kind of reference to that relationship (the mother/son relationship) why reinforce it so often when he’d already denounced it – saying his natural mom and family were of little importance (Matthew 12:48, 49)?

If he was talking about his birth through "natural processes", then either he was lying big time or the Gospel writers were. Starting a life from the womb of an untouched virgin is kinda unnatural today – and I’d be willing to bet it wasn’t a daily occurrence 2000 years ago either. If you add on to that a conception through a "visit" from the Holy Spirit. . . well, I’m convinced we’re not talking normal or natural here.

What Jesus was really trying to get across was:

"I came in to this world because of Man."
"I have the nature and the characteristics of Man."
"I breathe, eat, etc. like Man."
"I resemble my parent(s)."

In the same light, Jesus used the Son of God to mean:

"I came in to this world because of God." (John 3:16)
"I have the nature and the characteristics of God." (John 5:19-21)
"I breathe, eat, etc. like God." (John 5:17, 19)
"I resemble my parent(s)." (John 14:9)

Are you a child of God? Then, let’s be Perfect – the same way as our heavenly parent is perfect.