If you are new and playing on king then you wanted a challenge, didnt you?
Whats the problem?
He's also full of BS if he's telling you that he lost as Babylon. At science, no less.
My friend who's had Civ 5 for a fairly decent time and regularly plays against Deity computers says the earliest he's lost to a science victory was a 1940 by Babylon...
Being new you should start on Easy until you get better.
King is rather high for the first Civ V game ever. Prince is a good level. If you get your head handed too you, but have a good reason why, you're well on the way to mastering it. But if you have no idea where things went wrong, then it's too high a level.