You are saying that an omniscient didn't foresee all this? And being omnipotent, create it in the first place?
Of course not...but God gave man free will...or else man would not be human but a robot and man choose his fate, in addtion because God KNEW what man would choose He KNEW that He would sacrifice His only Son and His Son offered His life freely to reestablish the relationship between God and his Creation
Why?
One word
Love