The 30 second Gospel:
Well, this is only me clocking in here. I'm not the end-all be-all, know-it-all bible scholar, but as I understand it:
God gave us the 10 commandments so that we could learn that it is utterly impossible for humans to keep them all. (If any of them, half the time). ;o)
In our coming to such a conclusion, we would recognize our failure and consequently, our need for help.
Since God is perfect then, and humans not, God would have a big problem.
Since God is perfect, He can't be surrounded by that which is imperfect.
Imperfection must be utterly destroyed.
God also desperately loves His creation and most profoundly, the humans which He created in His own image.
So God has a problem.
He has to destroy imperfection, which we all are, but He also loves us all desperately.
Hence His need to come to earth.
He came into this world as both God and Man, and was born to a Virgin.
He lived a perfect life, as only God can, while undergoing all of the trials and temptations, troubles, pain and experiences and general crappy stuff that we suffer through as humans.
Then He allowed Himself to be destroyed on our behalf, even though he did not earn the destruction, we did.
Taking upon Himself the destruction that God the Father required of the offending items (us).
So God basically solved His own problem by starting with the 10 Commandments and ending with Jesus Christ.
That's the most basic, bare-bones gist of it.
It is a gigantic theological question that has plagued and confused people for millennia. :o)
Sometimes Jesus moved the signs.
He sometimes sent them God-knows-where,
just for the heck of it.
Just for the craic.